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```									                                   CHAPTER NINE

Statistical Inference:
Hypothesis Testing for Single Populations

B      1.   Hypothesis testing is derived from the mathematical notion of _______.

M           A.   direct proof
Term        B.   indirect proof
C.   margin of error
D.   infinity

C      2.   The first step in testing a hypothesis is to establish _______.

E           A.   an not rejectance hypothesis and a rejection hypothesis
Term        B.   a power function
C.   a null hypothesis and alternative hypothesis
D.   an indirect hypothesis

265
266    Test Bank

B      3.   In testing hypotheses, the researcher initially assumes that the _______.

E           A.   alternative hypothesis is true.
Term        B.   null hypothesis is true
D.   the population parameter of interest is known

A      4.   Consider the following null and alternative hypotheses.
Ho:   7
Ha:  > 6
These hypotheses _______________.

E           A.   are not mutually exclusive
App         B.   are not collectively exhaustive
C.   do not reference a population parameter
D.   are established correctly

D      5.   Consider the following null and alternative hypotheses.
Ho:   7
Ha:  > 7
These hypotheses _______________.

E           A.   are not mutually exclusive
App         B.   are not collectively exhaustive
C.   do not reference a population parameter
D.   are established correctly

B      6.   Consider the following null and alternative hypotheses.
Ho:   7
Ha:  < 6
These hypotheses _______________.

E           A.   are not mutually exclusive
App         B.   are not collectively exhaustive
C.   do not reference a population parameter
D.   are established correctly
Chapter 9: Statistical Inference: Hypothesis Testing for Single Populations   267

A      7.   Consider the following null and alternative hypotheses.
Ho:   78
Ha:  < 81
These hypotheses _______________.

E           A.   are not mutually exclusive
App         B.   are not collectively exhaustive
C.   do not reference a population parameter
D.   are established correctly

C      8.   Consider the following null and alternative hypotheses.
Ho: x  352
Ha: x > 352
These hypotheses _______________.

E           A.   are not mutually exclusive
App         B.   are not collectively exhaustive
C.   do not reference a population parameter
D.   are established correctly

C      9.   Consider the following null and alternative hypotheses.
Ho: p  0.61


Ha: p > 0.61
These hypotheses _______________.

E           A.   are not mutually exclusive
App         B.   are not collectively exhaustive
C.   do not reference a population parameter
D.   are established correctly

C     10.   Consider the following null and alternative hypotheses.
Ho: P  0.39
Ha: P > 0.39
These hypotheses _______________.

E           A.   are not mutually exclusive
App         B.   are not collectively exhaustive
C.   do not reference a population parameter
D.   are established correctly
268    Test Bank

C     11.   Consider the following null and alternative hypotheses.
Ho: S  558
Ha: S < 558
These hypotheses _______________.

E           A.   are not mutually exclusive
App         B.   are not collectively exhaustive
C.   do not reference a population parameter
D.   are established correctly

D     12.   Consider the following null and alternative hypotheses.
Ho: 2  35
Ha: 2 < 35
These hypotheses _______________.

E           A.   are not mutually exclusive
App         B.   are not collectively exhaustive
C.   do not reference a population parameter
D.   are established correctly

D     13.   The region of the distribution in hypothesis testing in which the null hypothesis is
rejected is called the _______.

E           A.   not rejectance region
Term        B.   null region
C.   alternative region
D.   rejection region

B     14.   The rejection and not rejectance regions are divided by a point called the _______.

E           A.   dividing point
Term        B.   critical value
C.   rejection value
D.   not rejectance value

B     15.   The portion of the distribution which is not in the rejection region is called the
_______.

E           A.   tolerable region
Term        B.   not rejectance region
C.   null region
D.   alternative region
Chapter 9: Statistical Inference: Hypothesis Testing for Single Populations     269

A   16.   The probability of committing a Type I error is called _______.

E         A.   the level of significance
Term      B.   beta
C.   the power of the test
D.   reliability

A   17.   The probability of committing a Type I error is called _______.

E         A.   
Term      B.   
C.   
D.   

A   18.   In statistical hypothesis testing, another name for  is _______.

E         A.   level of significance
Term      B.   power
C.   beta
D.   Type II error probability

C   19.   When a null hypothesis is rejected, the probability of committing a Type II error is
_______.

M         A.   
Term      B.   
C.   0
D.   1-

B   20.   When a true null hypothesis is rejected, the researcher has made a _______.

M         A.   Type II error
Term      B.   Type I error
C.   sampling error
D.   powerful error

C   21.   When a false null hypothesis is rejected, the researcher has made a _______.

M         A.   Type II error
Term      B.   Type I error
C.   correct decision
D.   powerful error
270    Test Bank

A     22.   When a researcher fails to reject a false null hypothesis, a ______ error has been
committed.

M           A.   Type II error
Term        B.   Type I error
C.   sampling error
D.   powerful error

C     23.   When a researcher fails to reject a null hypothesis, the probability of a Type I error
is ________.

M           A.   
Term        B.   
C.   0
D.   1-

B     24.   The probability of committing a Type II error is represented by _______.

M           A. 
Term        B. 
C. 1- 
D.  / 2

C     25.   Power is equal to _______.

M           A.   1-if the null hypothesis is true
Term        B.   if the null hypothesis is false
C.   1- if the null hypothesis is false
D.    if the null hypothesis is true

A     26.   Consider the following null and alternative hypotheses.
Ho:   67
Ha:  > 67
These hypotheses _______________.

E           A.   indicate a one-tailed test with a rejection area in the right tail
App         B.   indicate a one-tailed test with a rejection area in the left tail
C.   indicate a two-tailed test
D.   are established incorrectly
Chapter 9: Statistical Inference: Hypothesis Testing for Single Populations   271

B     27.   Consider the following null and alternative hypotheses.
Ho:   67
Ha:  < 67
These hypotheses _______________.

E           A.   indicate a one-tailed test with a rejection area in the right tail
App         B.   indicate a one-tailed test with a rejection area in the left tail
C.   indicate a two-tailed test
D.   are established incorrectly

C     28.   Consider the following null and alternative hypotheses.
Ho:  = 67
Ha:   67
These hypotheses _______________.

E           A.   indicate a one-tailed test with a rejection area in the right tail
App         B.   indicate a one-tailed test with a rejection area in the left tail
C.   indicate a two-tailed test
D.   are established incorrectly

A     29.   Consider the following null and alternative hypotheses.
Ho: P  0.16
Ha: P > 0.16
These hypotheses _______________.

E           A.   indicate a one-tailed test with a rejection area in the right tail
App         B.   indicate a one-tailed test with a rejection area in the left tail
C.   indicate a two-tailed test
D.   are established incorrectly

B     30.   Consider the following null and alternative hypotheses.
Ho: P  0.16
Ha: P < 0.16
These hypotheses _______________.

E           A.   indicate a one-tailed test with a rejection area in the right tail
App         B.   indicate a one-tailed test with a rejection area in the left tail
C.   indicate a two-tailed test
D.   are established incorrectly
272    Test Bank

C      31.   Consider the following null and alternative hypotheses.
Ho: P = 0.16
Ha: P  0.16
These hypotheses _______________.

E            A.   indicate a one-tailed test with a rejection area in the right tail
App          B.   indicate a one-tailed test with a rejection area in the left tail
C.   indicate a two-tailed test
D.   are established incorrectly

B      32.   Whenever hypotheses are established such that the alternative hypothesis is ">",
then this would be a _______.

E            A.   two-tailed test
Term         B.   one-tailed test
C.   Type II test
D.   Type I test

A      33.   Whenever hypotheses are established such that the alternative hypothesis is "not
equal to", then this would be a _______ test.

E            A.   two-tailed
Term         B.   one-tailed
C.   Type II
D.   Type I

A      34.   If, in testing hypotheses, the researcher uses a method in which the probability of
the calculated statistic is compared to alpha to reach a decision, the researcher is
using the _______.

E            A.   probability method
Term         B.   critical value method
C.   Z value method
D.   statistical method

A      35.   Suppose the alternative hypothesis in a hypothesis test is "the population mean is
greater than 65". If the sample size is 50 and alpha =.05, the critical value of Z is
_______.

M            A.   1.645
Calc         B.   -1.645
C.   1.96
D.   -1.96
Chapter 9: Statistical Inference: Hypothesis Testing for Single Populations        273

B      36.   Suppose the alternative hypothesis in a hypothesis test is "the population mean is
less than 60". If the sample size is 50 and alpha =.05, the critical value of Z is
_______.

M            A.   1.645
Calc         B.   -1.645
C.   1.96
D.   -1.96

C      37.   Suppose the alternative hypothesis in a hypothesis test is "the population mean is
greater than 60". If the sample size is 80 and alpha = .01, the critical value of Z is
_______.

M            A. 2.575
Calc         B. -2.575
C. 2.33
D. -2.33
D      38.   In a two-tailed hypothesis about a population mean with a sample size of 100 and
alpha = 0.10, the rejection region would be _______.

E            A.   Z>1.64
Calc         B.   Z>1.28
C.   Z<-1.28 and Z>1.28
D.   Z<-1.64 and Z>1.64

C      39.   In a two-tailed hypothesis about a population mean with a sample size of 100 and
alpha = 0.05, the rejection region would be _______.

E            A.   Z>1.64
Calc         B.   Z>1.96
C.   Z<-1.96 and Z>1.96
D.   Z<-1.64 and Z>1.64

C      40.   Suppose you are testing the null hypothesis that a population mean is less than or
equal to 80, against the alternative hypothesis that the population mean is greater
than 80. If the sample size is 49 and alpha = .10, the critical value of Z is
_______.

M            A.   1.645
Calc         B.   -1.645
C.   1.28
D.   -1.28
274    Test Bank

A      41.   Suppose you are testing the null hypothesis that a population mean is less than or
equal to 80, against the alternative hypothesis that the population mean is greater
than 80. If the sample size is 49 and alpha =.05, the critical value of Z is
_______.

M            A.   1.645
Calc         B.   -1.645
C.   1.96
D.   -1.96

A      42.   Suppose you are testing the null hypothesis that a population mean is less than or
equal to 80, against the alternative hypothesis that the population mean is greater
than 80. The sample size is 49 and alpha =.05. If the sample mean is 84 and the
sample standard deviation is 14, the calculated Z value is _______.

M            A.   2
Calc         B.   -2
C.   14
D.   -14

A      43.   Suppose you are testing the null hypothesis that a population mean is greater than
or equal to 60, against the alternative hypothesis that the population mean is less
than 60. The sample size is 64 and =.05. If the sample mean is 58 and the
sample standard deviation is 16, the calculated Z value is _______.

M            A.   -1
Calc         B.   1
C.   -8
D.   8

C      44.   Suppose a researcher is testing a null hypothesis that  = 61. A random sample of
n = 36 is taken resulting in a sample mean of 63 and S=9. The calculated Z value
is _______.

M            A.   -0.22
Calc         B.   0.22
C.   1.33
D.   8
Chapter 9: Statistical Inference: Hypothesis Testing for Single Populations    275

B     45.   A researcher is testing a hypothesis of a single mean. The critical Z value for 
=.05 and a one-tailed test is 1.645. The calculated Z value from sample data is
1.13. The decision made by the researcher based on this information is to ______
the null hypothesis.

M           A.   reject
App         B.   not reject
C.   redefine
D.   change the alternate hypothesis into

B     46.   A researcher is testing a hypothesis of a single mean. The critical Z value for 
=.05 and a two-tailed test is +1.96. The calculated Z value from sample data is
-1.85. The decision made by the researcher based on this information is to _____
the null hypothesis.

M           A.   reject
App         B.   not reject
C.   redefine
D.   change the alternate hypothesis into

A     47.   A researcher is testing a hypothesis of a single mean. The critical Z value for 
=.05 and a two-tailed test is +1.96. The calculated Z value from sample data is
2.85. The decision made by the researcher based on this information is to _____
the null hypothesis.

M           A.   reject
App         B.   not reject
C.   redefine
D.   change the alternate hypothesis into

A     48.   A researcher is testing a hypothesis of a single mean. The critical Z value for 
=.05 and a two-tailed test is +1.96. The calculated Z value from sample data is -
2.11. The decision made by the researcher based on this information is to _____
the null hypothesis.

M           A.   reject
App         B.   not reject
C.   redefine
D.   change the alternate hypothesis into
276    Test Bank

A     49.   A researcher is testing a hypothesis of a single mean. The critical Z value for =
.01 and a one-tailed test is -2.33. The calculated Z value from sample data is
-2.45. The decision made by the researcher based on this information is to
_________ the null hypothesis.

M           A.   reject
App         B.   not reject
C.   redefine
D.   change the alternate hypothesis into

A     50.   A researcher has a theory that the average age of managers in a particular industry
is over 35-years-old, and he wishes to prove this. The null hypothesis to conduct
a statistical test on this theory would be ____________.

M           A.   the population mean is < 35
App         B.   the population mean is > 35
C.   the population mean is = 35
D.   the population mean is > 35

D     51.   A company produces an item that is supposed to have a six inch hole punched in
the center. A quality control inspector is concerned that the machine which
punches the hole is "out-of-control" (hole is too large or too small). In an effort to
test this, the inspector is going to gather a sample punched by the machine and
measure the diameter of the hole. The alternative hypothesis used to statistical test
to determine if the machine is out-of-control is

M           A.   the mean diameter is > 6 inches
BApp        B.   the mean diameter is < 6 inches
C.   the mean diameter is = 6 inches
D.   the mean diameter is not equal to 6 inches

D     52.   Jennifer Cantu, VP of Customer Services at Tri-State Auto Insurance, Inc.,
monitors the claims processing time of the claims division. Her standard includes
"a mean processing time of 5 days or less." Each week, her staff checks for
compliance by analyzing a random sample of 60 claims. Jennifer's null
hypothesis is ________.

E           A.   >5
BApp        B.   >5
C.   n = 60
D.   5
Chapter 9: Statistical Inference: Hypothesis Testing for Single Populations   277

A   53.   Jennifer Cantu, VP of Customer Services at Tri-State Auto Insurance, Inc.,
monitors the claims processing time of the claims division. Her standard includes
"a mean processing time of 5 days or less." Each week, her staff checks for
compliance by analyzing a random sample of 60 claims. Jennifer's alternative
hypothesis is ________.

E         A.  > 5
BApp      B.   5
C. n = 60
D.   5
C   54.   Jennifer Cantu, VP of Customer Services at Tri-State Auto Insurance, Inc.,
monitors the claims processing time of the claims division. Each week, her staff
randomly selects a sample of 60 claims and tests the null hypothesis that the
"mean processing time is 5 days or less." Jennifer chooses a 0.05 level of
significance, the critical Z value is _____.

E         A.   1.96
BCalc     B.   -1.96
C.   1.645
D.   -1.645

B   55.   Jennifer Cantu, VP of Customer Services at Tri-State Auto Insurance, Inc.,
monitors the claims processing time of the claims division. Each week, her staff
randomly selects a sample of 60 claims and tests the null hypothesis that the
"mean processing time is 5 days or less." Jennifer chooses a 0.01 level of
significance, the critical Z value is _____.

E         A.   -2.33
BCalc     B.   2.33
C.   -2.58
D.   2.58
278    Test Bank

C    56.   Jennifer Cantu, VP of Customer Services at Tri-State Auto Insurance, Inc.,
monitors the claims processing time of the claims division. Each week, her staff
randomly selects a sample of 64 claims and tests the null hypothesis that the
"mean processing time is 5 days or less" using a 0.10 level of significance. Last
week the sample mean and standard deviation were 5.2 days and 0.56 days,
respectively. The calculated Z value is _____.

M          A.   0.36
BCalc      B.   1.28
C.   2.86
D.   2.91

D    57.   Jennifer Cantu, VP of Customer Services at Tri-State Auto Insurance, Inc.,
monitors the claims processing time of the claims division. Each week, her staff
randomly selects a sample of 64 claims and tests the null hypothesis that the
"mean processing time is 5 days or less" using a 0.05 level of significance. Last
week the sample mean and standard deviation were 5.2 days and 0.56 days,
respectively. The appropriate decision is _____.

H          A.   reduce the sample size
BCalc      B.   increase the sample size
C.   do not reject the null hypothesis
D.   reject the null hypothesis

C    58.   Jennifer Cantu, VP of Customer Services at Tri-State Auto Insurance, Inc.,
monitors the claims processing time of the claims division. Each week, her staff
randomly selects a sample of 64 claims and tests the null hypothesis that the
"mean processing time is 5 days or less" using a 0.05 level of significance. Last
week the sample mean and standard deviation were 5.2 days and 1.56 days,
respectively. The appropriate decision is _____.

H          A.   reduce the sample size
BCalc      B.   increase the sample size
C.   do not reject the null hypothesis
D.   reject the null hypothesis
Chapter 9: Statistical Inference: Hypothesis Testing for Single Populations    279

A   59.   Restaurateur Denny Valentine is evaluating the feasibility of opening a restaurant
in Richmond. The Chamber of Commerce estimates that "Richmond families, on
the average, dine out at least 3 evenings per week." Denny plans to test this
hypothesis using a random sample of 81 Richmond families. His null hypothesis
is __________.

E         A.   3
BApp      B.   3
C.   n = 81
D.   <3

C   60.   Restaurateur Denny Valentine is evaluating the feasibility of opening a restaurant
in Richmond. The Chamber of Commerce estimates that "Richmond families, on
the average, dine out at least 3 evenings per week." Denny plans to test this
hypothesis using a random sample of 81 Richmond families. His alternative
hypothesis is __________.

E         A.   3
BApp      B.   <3
C.   <3
D.   n = 81

A   61.   Restaurateur Denny Valentine is evaluating the feasibility of opening a restaurant
in Richmond. The Chamber of Commerce estimates that "Richmond families, on
the average, dine out at least 3 evenings per week." Denny plans to test this
hypothesis at the 0.05 level of significance using a random sample of 81
Richmond families. The critical Z value is __________.

E         A.   -1.645
BCalc     B.   1.645
C.   -1.96
D.   1.96
280    Test Bank

C    62.   Restaurateur Denny Valentine is evaluating the feasibility of opening a restaurant
in Richmond. The Chamber of Commerce estimates that "Richmond families, on
the average, dine out at least 3 evenings per week." Denny plans to test this
hypothesis at the 0.01 level of significance using a random sample of 81
Richmond families. The critical Z value is __________.

E          A.   -2.58
BCalc      B.   2.58
C.   -2.33
D.   2.33

A    63.   Restaurateur Denny Valentine is evaluating the feasibility of opening a restaurant
in Richmond. The Chamber of Commerce estimates that "Richmond families, on
the average, dine out at least 3 evenings per week." Denny plans to test this
hypothesis at the 0.01 level of significance. His random sample of 81 Richmond
families produced a mean and a standard deviation of 2.7 and 0.9 evenings per
week, respectively. The calculated Z value is __________.

M          A.   -3.00
BCalc      B.   3.00
C.   -0.33
D.   0.33

B    64.   Restaurateur Denny Valentine is evaluating the feasibility of opening a restaurant
in Richmond. The Chamber of Commerce estimates that "Richmond families, on
the average, dine out at least 3 evenings per week." Denny plans to test this
hypothesis at the 0.01 level of significance. His random sample of 81 Richmond
families produced a mean and a standard deviation of 2.7 and 0.9 evenings per
week, respectively. The appropriate decision is __________.

H          A.   do not reject the null hypothesis
BCalc      B.   reject the null hypothesis
C.   reduce the sample size
D.   increase the sample size
Chapter 9: Statistical Inference: Hypothesis Testing for Single Populations    281

B   65.   Restaurateur Denny Valentine is evaluating the feasibility of opening a restaurant
in Richmond. The Chamber of Commerce estimates that "Richmond families, on
the average, dine out at least 3 evenings per week." Denny plans to test this
hypothesis at the 0.01 level of significance. His random sample of 81 Richmond
families produced a mean and a standard deviation of 2.7 and 1.8 evenings per
week, respectively. The calculated Z value is __________.

M         A.   1.50
BCalc     B.   -1.50
C.   0.17
D.   -0.17

A   66.   Restaurateur Denny Valentine is evaluating the feasibility of opening a restaurant
in Richmond. The Chamber of Commerce estimates that "Richmond families, on
the average, dine out at least 3 evenings per week." Denny plans to test this
hypothesis at the 0.01 level of significance. His random sample of 81 Richmond
families produced a mean and a standard deviation of 2.7 and 1.8 evenings per
week, respectively. The appropriate decision is __________.

H         A.   do not reject the null hypothesis
BCalc     B.   reject the null hypothesis
C.   reduce the sample size
D.   increase the sample size

B   67.   Restaurateur Denny Valentine is evaluating the feasibility of opening a restaurant
in Richmond. The Chamber of Commerce estimates that "Richmond families, on
the average, dine out at least 3 evenings per week." Denny plans to test this
hypothesis at the 0.01 level of significance. His random sample of 81 Richmond
families produced a mean and a standard deviation of 2.5 and 1.8 evenings per
week, respectively. The appropriate decision is __________.

H         A.   do not reject the null hypothesis
BCalc     B.   reject the null hypothesis
C.   reduce the sample size
D.   increase the sample size
282    Test Bank

B    68.   When the rod shearing process at Stockton Steel is "in control" it produces rods
with a mean length of 120 inches. Periodically, quality control inspectors select a
random sample of 36 rods. If the mean length of sampled rods is too long or too
short, the shearing process is shut down. The null hypothesis is _________.

E          A.   n = 36
BApp       B.    = 120
C.     120
D.   n  36

C    69.   When the rod shearing process at Stockton Steel is "in control" it produces rods
with a mean length of 120 inches. Periodically, quality control inspectors select a
random sample of 36 rods. If the mean length of sampled rods is too long or too
short, the shearing process is shut down. The alternative hypothesis is
_________.

E          A.   n = 36
BApp       B.    = 120
C.     120
D.   n  36

D    70.   When the rod shearing process at Stockton Steel is "in control" it produces rods
with a mean length of 120 inches. Periodically, quality control inspectors select a
random sample of 36 rods. If the mean length of sampled rods is too long or too
short, the shearing process is shut down. Sarah Shum, Director of Quality
Programs, chose a 0.05 level of significance for this test. The critical Z values are
_________.

E          A.   -1.645 and 1.645
BCalc      B.   -1.75 and 1.75
C.   -2.33 and 2.33
D.   -1.96 and 1.96
Chapter 9: Statistical Inference: Hypothesis Testing for Single Populations      283

A   71.   When the rod shearing process at Stockton Steel is "in control" it produces rods
with a mean length of 120 inches. Periodically, quality control inspectors select a
random sample of 36 rods. If the mean length of sampled rods is too long or too
short, the shearing process is shut down. Sarah Shum, Director of Quality
Programs, chose a 0.10 level of significance for this test. The critical Z values are
_________.

E         A.   -1.645 and 1.645
BCalc     B.   -1.75 and 1.75
C.   -2.33 and 2.33
D.   -1.96 and 1.96

C   72.   When the rod shearing process at Stockton Steel is "in control" it produces rods
with a mean length of 120 inches. Periodically, quality control inspectors select a
random sample of 36 rods. If the mean length of sampled rods is too long or too
short, the shearing process is shut down. The last sample showed a mean and
standard deviation of 120.5 and 1.2 inches, respectively. Using  = 0.05, the
calculated Z value is _________.

M         A.   0.42
BCalc     B.   -0.42
C.   2.50
D.   -2.50

C   73.   When the rod shearing process at Stockton Steel is "in control" it produces rods
with a mean length of 120 inches. Periodically, quality control inspectors select a
random sample of 36 rods. If the mean length of sampled rods is too long or too
short, the shearing process is shut down. The last sample showed a mean and
standard deviation of 120.5 and 1.2 inches, respectively. Using  = 0.05, the
appropriate decision is _________.

H         A.   do not reject the null hypothesis and shut down the process
BCalc     B.   do not reject the null hypothesis and do not shut down the process
C.   reject the null hypothesis and shut down the process
D.   reject the null hypothesis and do not shut down the process
284    Test Bank

B      74.   When the rod shearing process at Stockton Steel is "in control" it produces rods
with a mean length of 120 inches. Periodically, quality control inspectors select a
random sample of 36 rods. If the mean length of sampled rods is too long or too
short, the shearing process is shut down. The last sample showed a mean and
standard deviation of 120.2 and 1.2 inches, respectively. Using  = 0.05, the
appropriate decision is _________.

H            A.   do not reject the null hypothesis and shut down the process
BCalc        B.   do not reject the null hypothesis and do not shut down the process
C.   reject the null hypothesis and shut down the process
D.   reject the null hypothesis and do not shut down the process

B      75.   In performing a hypothesis test where the null hypothesis is that the population
mean is 23 against the alternative hypothesis that the population mean is not equal
to 23, a random sample of 17 items is selected. The sample mean is 24.6 and the
sample standard deviation is 3.3. It can be assumed that the population is
normally distributed. The degrees of freedom associated with this are _______.

E            A.   17
Calc         B.   16
C.   15
D.   2

B      76.   In performing a hypothesis test where the null hypothesis is that the population
mean is 4.8 against the alternative hypothesis that the population mean is not
equal to 4.8, a random sample of 25 items is selected. The sample mean is 4.1
and the sample standard deviation is 1.4. It can be assumed that the population is
normally distributed. The degrees of freedom associated with this are _______.

E            A.   25
Calc         B.   24
C.   26
D.   2
Chapter 9: Statistical Inference: Hypothesis Testing for Single Populations    285

B      77.   In performing a hypothesis test where the null hypothesis is that the population
mean is 4.8 against the alternative hypothesis that the population mean is not
equal to 4.8, a random sample of 25 items is selected. The sample mean is 4.1
and the sample standard deviation is 1.4. It can be assumed that the population is
normally distributed. The level of significance is selected to be 0.10. The table
"t" value for this problem is _______.

E            A.   1.318
Calc         B.   1.711
C.   2.492
D.   2.797

C      78.   In performing a hypothesis test where the null hypothesis is that the population
mean is 4.8 against the alternative hypothesis that the population mean is not
equal to 4.8, a random sample of 25 items is selected. The sample mean is 4.1
and the sample standard deviation is 1.4. It can be assumed that the population is
normally distributed. The computed "t" value for this problem is _______.

E            A.   -12.5
Calc         B.   12.5
C.   -2.5
D.   -0.7

C      79.   In performing a hypothesis test where the null hypothesis is that the population
mean is 6.9 against the alternative hypothesis that the population mean is not
equal to 6.9, a random sample of 16 items is selected. The sample mean is 7.1
and the sample standard deviation is 2.4. It can be assumed that the population is
normally distributed. The computed "t" value for this problem is _______.

M            A.   0.05
Calc         B.   0.20
C.   0.33
D.   1.33
286    Test Bank

D      80.   In performing a hypothesis test where the null hypothesis is that the population
mean is 6.9 against the alternative hypothesis that the population mean is not
equal to 6.9, a random sample of 16 items is selected. The sample mean is 7.1
and the sample standard deviation is 2.4. It can be assumed that the population is
normally distributed. The level of significance is selected as 0.05. The table "t"
value for this problem is _______.

E            A.   1.753
Calc         B.   2.947
C.   2.120
D.   2.131

A      81.   In performing a hypothesis test where the null hypothesis is that the population
mean is 6.9 against the alternative hypothesis that the population mean is not
equal to 6.9, a random sample of 16 items is selected. The sample mean is 7.1
and the sample standard deviation is 2.4. It can be assumed that the population is
normally distributed. The level of significance is selected as 0.05. The decision
rule for this problem is to reject the null hypothesis if the computed "t" value is
_______.

M            A.   less than -2.131 or greater than 2.131
Calc         B.   less than -1.761 or greater than 1.761
C.   less than -1.753 or greater than 1.753
D.   less than -2.120 or greater than 2.120

C      82.   The diameter of 3.5 inch diskettes is normally distributed. Periodically, quality
control inspectors at Dallas Diskettes randomly select a sample of 16 diskettes. If
the mean diameter of the diskettes is too large or too small the diskette punch is
shut down for adjustment; otherwise, the punching process continues. The null
hypothesis is _______.

E            A.   n  16
BApp         B.   n = 16
C.    = 3.5
D.     3.5
Chapter 9: Statistical Inference: Hypothesis Testing for Single Populations     287

B   83.   The diameter of 3.5 inch diskettes is normally distributed. Periodically, quality
control inspectors at Dallas Diskettes randomly select a sample of 16 diskettes. If
the mean diameter of the diskettes is too large or too small the diskette punch is
shut down for adjustment; otherwise, the punching process continues. The last
sample showed a mean and standard deviation of 3.49 and 0.08 inches,
respectively. Using  = 0.05, the critical "t" values are _______.

E         A.   -2.120 and 2.120
BCalc     B.   -2.131 and 2.131
C.   -1.753 and 1.753
D.   -1.746 and 1.746

D   84.   The diameter of 3.5 inch diskettes is normally distributed. Periodically, quality
control inspectors at Dallas Diskettes randomly select a sample of 16 diskettes. If
the mean diameter of the diskettes is too large or too small the diskette punch is
shut down for adjustment; otherwise, the punching process continues. The last
sample showed a mean and standard deviation of 3.49 and 0.08 inches,
respectively. Using  = 0.05, the appropriate decision is _______.

H         A.   reject the null hypothesis and shut down the punch
BCalc     B.   reject the null hypothesis and do not shut down the punch
C.   do not reject the null hypothesis and shut down the punch
D.   do not reject the null hypothesis and do shut down the punch

A   85.   The diameter of 3.5 inch diskettes is normally distributed. Periodically, quality
control inspectors at Dallas Diskettes randomly select a sample of 16 diskettes. If
the mean diameter of the diskettes is too large or too small the diskette punch is
shut down for adjustment; otherwise, the punching process continues. The last
sample showed a mean and standard deviation of 3.55 and 0.08 inches,
respectively. Using  = 0.05, the appropriate decision is _______.

H         A.   reject the null hypothesis and shut down the punch
BCalc     B.   reject the null hypothesis and do not shut down the punch
C.   do not reject the null hypothesis and shut down the punch
D.   do not reject the null hypothesis and do not shut down the punch
288    Test Bank

C      86.   In performing hypothesis test about the population mean, the population standard
deviation should be used if it is known. If it is not known, for large samples it can
be approximated by _______.

E            A.   the sample mean
Term         B.   the sample size
C.   the sample standard deviation
D.   the population variance

A      87.   In performing hypothesis test about the population mean, the population standard
deviation should be used if it is known. If it is not known, it can be approximated
by the sample standard deviation if _______.

M            A.   the sample size is at least thirty
Term         B.   the sample is random
C.   the population mean is known
D.   the alpha is less than 0.10

A      88.   A political scientist wants to prove that a candidate is currently carrying more than
60% of the vote in the state. She has her assistants randomly sample 200 eligible
voters in the state by telephone and only 90 declare that they support her
candidate. The calculated Z value for this problem is _______.

M            A.   -4.33
Calc         B.   4.33
C.   0.45
D.   -.31

B      89.   A company believes that it controls more than 30% of the total market share for
one of its products. To prove this belief, a random sample of 144 purchases of this
product are contacted. It is found that 50 of the 144 purchased this company's
brand of the product. If a researcher wants to conduct a statistical test for this
problem, the alternative hypothesis would be _______.

M            A.   the population proportion is less than 0.30
BApp         B.   the population proportion is greater than 0.30
C.   the population proportion is not equal to 0.30
D.   the population mean is less than 40
Chapter 9: Statistical Inference: Hypothesis Testing for Single Populations    289

D   90.   A company believes that it controls more than 30% of the total market share for
one of its products. To prove this belief, a random sample of 144 purchases of this
product are contacted. It is found that 50 of the 144 purchased this company's
brand of the product. If a researcher wants to conduct a statistical test for this
problem, the calculated Z value would be _______.

M         A.   0.05
BCalc     B.   0.103
C.   0.35
D.   1.24

A   91.   A company believes that it controls more than 30% of the total market share for
one of its products. To prove this belief, a random sample of 144 purchases of this
product are contacted. It is found that 50 of the 144 purchased this company's
brand of the product. If a researcher wants to conduct a statistical test for this
problem, the test would be _______.

E         A.   a one-tailed test
BApp      B.   a two-tailed test
C.   an alpha test
D.   a finite population test

B   92.   Ophelia O'Brien, VP of Consumer Credit of American First Banks (AFB),
monitors the default rate on personal loans at the AFB member banks. One of her
standard's is "no more than 5% of personal loans should be in default." On each
Friday, the default rate is calculated for a sample of 500 personal loans. Last
Friday's sample contained 30 defaulted loans. Ophelia's null hypothesis is
_______.

E         A.   P > 0.05
BApp      B.   P  0.05
C.   n = 30
D.   n = 500
290    Test Bank

C    93.   Ophelia O'Brien, VP of Consumer Credit of American First Banks (AFB),
monitors the default rate on personal loans at the AFB member banks. One of her
standard's is "no more than 5% of personal loans should be in default." On each
Friday, the default rate is calculated for a sample of 500 personal loans. Last
Friday's sample contained 30 defaulted loans. Using  = 0.10, the critical Z value
is _______.

E          A.   1.645
BCalc      B.   -1.645
C.   1.28
D.   -1.28

A    94.   Ophelia O'Brien, VP of Consumer Credit of American First Banks (AFB),
monitors the default rate on personal loans at the AFB member banks. One of her
standard's is "no more than 5% of personal loans should be in default." On each
Friday, the default rate is calculated for a sample of 500 personal loans. Last
Friday's sample contained 30 defaulted loans. Using  = 0.10, the calculated Z
value is _______.

M          A.   1.03
BCalc      B.   -1.03
C.   0.046
D.   -0.046

D    95.   Ophelia O'Brien, VP of Consumer Credit of American First Banks (AFB),
monitors the default rate on personal loans at the AFB member banks. One of her
standard's is "no more than 5% of personal loans should be in default." On each
Friday, the default rate is calculated for a sample of 500 personal loans. Last
Friday's sample contained 30 defaulted loans. Using  = 0.10, the appropriate
decision is _______.

H          A.   reduce the sample size
BCalc      B.   increase the sample size
C.   reject the null hypothesis
D.   do not reject the null hypothesis
Chapter 9: Statistical Inference: Hypothesis Testing for Single Populations   291

C   96.   Ophelia O'Brien, VP of Consumer Credit of American First Banks (AFB),
monitors the default rate on personal loans at the AFB member banks. One of her
standard's is "no more than 5% of personal loans should be in default." On each
Friday, the default rate is calculated for a sample of 500 personal loans. Last
Friday's sample contained 38 defaulted loans. Using  = 0.10, the appropriate
decision is _______.

H         A.   reduce the sample size
BCalc     B.   increase the sample size
C.   reject the null hypothesis
D.   do not reject the null hypothesis

C   97.   The executives of CareFree Insurance, Inc. feel that "a majority of our employees
perceive a participatory management style at CareFree." A random sample of 200
CareFree employees is selected to test this hypothesis at the 0.05 level of
significance. Eighty employees rate the management as participatory. The null
hypothesis is __________.

E         A.   n = 30
BApp      B.   n = 200
C.   P  0.50
D.   P < 0.50

A   98.   The executives of CareFree Insurance, Inc. feel that "a majority of our employees
perceive a participatory management style at CareFree." A random sample of 200
CareFree employees is selected to test this hypothesis at the 0.05 level of
significance. Eighty employees rate the management as participatory. The critical
Z value is __________.

E         A.   -1.645
BCalc     B.   1.645
C.   -1.96
D.   1.96
292    Test Bank

B    99.   The executives of CareFree Insurance, Inc. feel that "a majority of our employees
perceive a participatory management style at CareFree." A random sample of 200
CareFree employees is selected to test this hypothesis at the 0.05 level of
significance. Eighty employees rate the management as participatory. The
appropriate decision is __________.

H          A.   do not reject the null hypothesis
BCalc      B.   reject the null hypothesis
C.   reduce the sample size
D.   increase the sample size

A 100.     The executives of CareFree Insurance, Inc. feel that "a majority of our employees
perceive a participatory management style at CareFree." A random sample of 200
CareFree employees is selected to test this hypothesis at the 0.05 level of
significance. Ninety employees rate the management as participatory. The
appropriate decision is __________.

H          A.   do not reject the null hypothesis
BCalc      B.   reject the null hypothesis
C.   reduce the sample size
D.   increase the sample size

D 101.     Elwin Osbourne, CIO at GFS, Inc., suspects that at least 25% of e-mail messages
sent by GFS employees are not business related. A random sample of 300 e-mail
messages was selected to test this hypothesis at the 0.01 level of significance.
Fifty-four of the messages were not business related. The null hypothesis is ____.

E          A.    = 30
BApp       B.   n = 300
C.   P < 0.25
D.   P  0.25

A 102.     Elwin Osbourne, CIO at GFS, Inc., suspects that at least 25% of e-mail messages
sent by GFS employees are not business related. A random sample of 300 e-mail
messages was selected to test this hypothesis at the 0.01 level of significance.
Fifty-four of the messages were not business related. The critical Z value is ____.

E          A.   
BApp       B.   -1.96
C.   1.96
D.   2.57
Chapter 9: Statistical Inference: Hypothesis Testing for Single Populations   293

C 103.   Elwin Osbourne, CIO at GFS, Inc., suspects that at least 25% of e-mail messages
sent by GFS employees are not business related. A random sample of 300 e-mail
messages was selected to test this hypothesis at the 0.01 level of significance.
Fifty-four of the messages were not business related. The appropriate decision is
_______.

E        A.   increase the sample size
BApp     B.   gather more data
C.   reject the null hypothesis
D.   do not reject the null hypothesis

C 104.   Elwin Osbourne, CIO at GFS, Inc., suspects that at least 25% of e-mail messages
sent by GFS employees are not business related. A random sample of 300 e-mail
messages was selected to test this hypothesis at the 0.01 level of significance.
Sixty of the messages were not business related. The appropriate decision is
_______.

E        A.   increase the sample size
BApp     B.   gather more data
C.   reject the null hypothesis
D.   do not reject the null hypothesis

A 105.   A two tailed hypothesis test about the mean is performed. The calculated Z value
is 1.78. If alpha = 0.05, the correct decision would be _______.

M        A.   do not reject the null hypothesis
Calc     B.   reject the null hypothesis
C.   take a larger sample
D.   get a new calculator

B 106.   A two tailed hypothesis test about the mean is performed. The calculated Z value
is 1.78. If alpha = 0.10, the correct decision would be _______.

M        A.   do not reject the null hypothesis
Calc     B.   reject the null hypothesis
C.   take a larger sample
D.   get a new calculator
294   Test Bank

C 107.   A null hypothesis was rejected at the 0.10 level of significance. It the level of
significance were changed to 0.05 and the same sample results were obtained,

M        A.    reject the null hypothesis
App      B.    do not reject the null hypothesis
C.    cannot be determined without further information
D.    all of the above

B 108.   A null hypothesis was not rejected at the 0.10 level of significance. It the level of
significance were changed to 0.05 and the same sample results were obtained,

M        A.    reject the null hypothesis
App      B.    do not reject the null hypothesis
C.    cannot be determined without further information
D.    all of the above

B 109.   What happens to the rejection region if the level of significance is changed from
0.10 to 0.05?

E        A.    it gets larger
App      B.    it gets smaller
C.    it does not change
D.    all of the above

A 110.   What happens to the rejection region if the level of significance is changed from
0.05 to 0.10?

E        A.    it gets larger
App      B.    it gets smaller
C.    it does not change
D.    all of the above

D 111.   A null hypothesis is P > 0.65. To test this hypothesis, a sample of 400 is taken
and alpha is set at 0.05. If the true proportion is P = 0.60, what is the probability
of a type II error?

H        A.    0.17
Calc     B.    0.45
C.    0.95
D.    0.67
Chapter 9: Statistical Inference: Hypothesis Testing for Single Populations     295

D 112.   Discrete Components, Inc. manufactures a line of electrical resistors. Presently,
the carbon composition line is producing 100 ohm resistors. The population
variance of these resistors "must not exceed 4" to conform to industry standards.
Periodically, the quality control inspectors check for conformity by randomly
select 10 resistors from the line, and calculating the sample variance. The last
sample had a variance of 4.36. Using  = 0.05, the null hypothesis is
_________________.

E        A.    = 100
BApp     B.     10
C.   S2  4
D.   2  4

B 113.   Discrete Components, Inc. manufactures a line of electrical resistors. Presently,
the carbon composition line is producing 100 ohm resistors. The population
variance of these resistors "must not exceed 4" to conform to industry standards.
Periodically, the quality control inspectors check for conformity by randomly
select 10 resistors from the line, and calculating the sample variance. The last
sample had a variance of 4.36. Using  = 0.05, the critical value of chi-square is
_________________.

E        A.   18.31
BCalc    B.   16.92
C.   3.94
D.   3.33

D 114.   Discrete Components, Inc. manufactures a line of electrical resistors. Presently,
the carbon composition line is producing 100 ohm resistors. The population
variance of these resistors "must not exceed 4" to conform to industry standards.
Periodically, the quality control inspectors check for conformity by randomly
select 10 resistors from the line, and calculating the sample variance. The last
sample had a variance of 4.36. Using  = 0.05, the calculated value of chi-square
is _________________.

E        A.   1.74
BCalc    B.   1.94
C.   10.90
D.   9.81
296   Test Bank

D 115.   Discrete Components, Inc. manufactures a line of electrical resistors. Presently,
the carbon composition line is producing 100 ohm resistors. The population
variance of these resistors "must not exceed 4" to conform to industry standards.
Periodically, the quality control inspectors check for conformity by randomly
select 10 resistors from the line, and calculating the sample variance. The last
sample had a variance of 4.36. Using  = 0.05, the appropriate decision is
_________________.

H        A.    increase the sample size
BCalc    B.    reduce the sample size
C.    reject the null hypothesis
D.    do not reject the null hypothesis

B 116.   David Desreumaux, VP of Human Resources of American First Banks (AFB), is
reviewing the employee training programs of AFB banks. Based on a recent
census of personnel, David knows that the variance of teller training time in the
Southeast region is 8, and he wonders if the variance in the Southwest region is
the same number. His staff randomly selected personnel files for 15 tellers in the
Southwest Region, and determined that their mean training time was 25 hours and
that the standard deviation was 4 hours. Using  = 0.10, the null hypothesis is
________.

E        A.     = 25
BApp     B.    2 = 8
C.    2 = 4
D.    2  8

B 117.   David Desreumaux, VP of Human Resources of American First Banks (AFB), is
reviewing the employee training programs of AFB banks. Based on a recent
census of personnel, David knows that the variance of teller training time in the
Southeast region is 8, and he wonders if the variance in the Southwest region is
the same number. His staff randomly selected personnel files for 15 tellers in the
Southwest Region, and determined that their mean training time was 25 hours and
that the standard deviation was 4 hours. Using  = 0.10, the critical values of chi-
square are ________.

M        A.    7.96 and 26.30
BCalc    B.    6.57 and 23.68
C.    -1.96 and 1.96
D.    -1.645 and 1.645
Chapter 9: Statistical Inference: Hypothesis Testing for Single Populations   297

A 118.   David Desreumaux, VP of Human Resources of American First Banks (AFB), is
reviewing the employee training programs of AFB banks. Based on a recent
census of personnel, David knows that the variance of teller training time in the
Southeast region is 8, and he wonders if the variance in the Southwest region is
the same number. His staff randomly selected personnel files for 15 tellers in the
Southwest Region, and determined that their mean training time was 25 hours and
that the standard deviation was 4 hours. Using  = 0.10, the calculated value of
chi-square is ________.

E        A.   28.00
BCalc    B.   30.00
C.   56.00
D.   60.00

D 119.   David Desreumaux, VP of Human Resources of American First Banks (AFB), is
reviewing the employee training programs of AFB banks. Based on a recent
census of personnel, David knows that the variance of teller training time in the
Southeast region is 8, and he wonders if the variance in the Southwest region is
the same number. His staff randomly selected personnel files for 15 tellers in the
Southwest Region, and determined that their mean training time was 25 hours and
that the standard deviation was 4 hours. Using  = 0.10, the appropriate decision
is ________.

H        A.   increase the sample size
BCalc    B.   reduce the sample size
C.   do not reject the null hypothesis
D.   reject the null hypothesis
298   Test Bank

120.   The last operation on the 'dry line' at Canine Delights is a semiautomatic bag
filling step. The dry line mixes, shapes, dries, and bags the five dry dog foods
(one at a time) in Canine Delights' product line. Each of the five mixes is offered
in 4 different sizes (5, 10, 15, and 25 pounds). When the bag filling machine is
properly adjusted, the mean weight of the filled bags equals the advertised weight.
Even so, the weight varies from bag to bag.

Discuss statistical procedures for controlling the bag filling operation. Other than
improper adjustment of the machine, what factors may account for the variability
of the bags weights, or for an upward (downward) drift in the mean bag weight?
What are the consequences of significantly overfilling (underfilling) the bags?
M         _________________________________________________________________
BApp      _________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
Chapter 9: Statistical Inference: Hypothesis Testing for Single Populations     299

121.   Carlos Cavazos, Director of Human Resources, is developing plans for an
employee morale 'barometer.' First, he plans to measure the current morale level
to use as a benchmark. Then, periodic (possibly monthly) measurements will be
taken to track increases (decreases). His primary measuring instrument will be
several 5-point scaled items (1 = totally depressed, 5 = it doesn't get any better
than this). Carlos believes that, after the bugs are worked out, the system will
allow management to assess the impact of managerial actions on employee
morale.

Describe the statistical methods which will be useful to Carlos, during the design
and implementation of the morale barometer. What are the limitations of this
system? What factors affect employee morale?
M        _________________________________________________________________
BApp     _________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
300   Test Bank

122.   Alan Lessoff, VP of Marketing at CyberWarehouse, Inc. (CWI), wants to know
what makes a good web site for online shoppers. What design factors of a web
site increase repeat visits by web shoppers? Color schemes? Graphics?
Animations? Audio? Organization of pages? Ease of navigation? Opinion
polls? E-mail feedback?

Representatives of Web Shoppe Designs (WSD) claim that their team knows, and
offer Alan a test trial of their design. Alan is inclined to accept the offer since it
would be hosted, at no expense to CWI, on WSD's servers during the trial period.

Alan has accumulated an extensive database of demographic data, and frequency
of visits of repeat visitors to CWI web sites. The WSD representatives will
collect comparable data during the trial period.

Describe the statistical methods which will be useful to Alan at the conclusion of
the trial period.
M
BApp
Chapter 9: Statistical Inference: Hypothesis Testing for Single Populations     301

123.   Online financial brokerages continue go grow with the Internet. CyberMarkets,

Addalie McMinn, VP of Research at CMI, expects increasingly intense
competition between online brokerages for new customers as the industry
wants to understand "what makes them tick," so she can advise CMI clients how
to compete more successfully. What factors do these investors use to choose one
broker over another? Transaction costs? Basic service characteristics such as fast
order execution, and timely, well-organized statements? Free tie-in services such

Should Addalie segment the customer population? Are all factors equally
important for all market segments? Does age matter? Does gender matter? Does
profession matter?