# Identify the null hypothesis alternative hypothesis test statistic Math 227 Chapter 8 Test

### Pages to are hidden for

"Identify the null hypothesis alternative hypothesis test statistic Math 227 Chapter 8 Test"

##### Please download to view full document

Math 227 (Chapter 8 Test)                                   Name:

Identify the null hypothesis, alternative hypothesis, test statistic, P-value, conclusion about the null hypothesis, and final
conclusion that addresses the original claim.
Section 8.3
1) A supplier of 3.5" disks claims that no more than 1% of the disks are defective. In a random 1)
sample of 600 disks, it is found that 3% are defective, but the supplier claims that this is
only a sample fluctuation. At the 0.01 level of significance, test the supplier's claim that no
more than 1% are defective.

2) In a sample of 167 children selected randomly from one town, it is found that 37 of them        2)
suffer from asthma. At the 0.05 significance level, test the claim that the proportion of all
children in the town who suffer from asthma is 11%.

3) In a clinical study of an allergy drug, 108 of the 202 subjects reported experiencing           3)
significant relief from their symptoms. At the 0.01 significance level, test the claim that
more than half of all those using the drug experience relief.

Section 8.4
4) The health of employees is monitored by periodically weighing them in. A sample of 54           4)
employees has a mean weight of 183.9 lb. Assuming that is known to be 121.2 lb, use a
0.10 significance level to test the claim that the population mean of all such employees
weights is less than 200 lb.

5) A random sample of 100 pumpkins is obtained and the mean circumference is found to be           5)
40.5 cm. Assuming that the population standard deviation is known to be 1.6 cm, use a 0.05
significance level to test the claim that the mean circumference of all pumpkins is equal to
39.9 cm.

1
Determine whether the hypothesis test involves a sampling distribution of means that is a normal distribution, Student t
distribution, or neither.
6) Claim: µ = 78. Sample data: n = 24, x = 101, s = 15.3. The sample data appear to come from    6)
a population with a distribution that is very far from normal, and is unknown.

Section 8.5
Test the given claim using the traditional method of hypothesis testing. Assume that the sample has been randomly
selected from a population with a normal distribution.
7) In tests of a computer component, it is found that the mean time between failures is 520  7)
hours. A modification is made which is supposed to increase the time between failures.
Tests on a random sample of 10 modified components resulted in the following times (in
hours) between failures.
518     548 561 523         536 499 538 557 528 563
At the 0.05 significance level, test the claim that for the modified components, the mean
time between failures is greater than 520 hours.

8) A manufacturer makes ball bearings that are supposed to have a mean weight of 30 g. A         8)
retailer suspects that the mean weight is actually less than 30 g. The mean weight for a
random sample of 16 ball bearings is 29 g with a standard deviation of 3.9 g. At the 0.05
significance level, test the claim that the mean is less than 30 g.

Section 8.6
Use the traditional method to test the given hypothesis. Assume that the population is normally distributed and that the
sample has been randomly selected.
9) The standard deviation of math test scores at one high school is 16.1. A teacher claims that    9)
the standard deviation of the girls' test scores is smaller than 16.1. A random sample of 22
girls results in scores with a standard deviation of 14.3. Use a significance level of 0.01 to
test the teacher's claim.

10) Systolic blood pressure levels for men have a standard deviation of 19.7 mm Hg. A random      10)
sample of 31 women resulted in blood pressure levels with a standard deviation of 23.2
mm Hg. Use a 0.05 significance level to test the claim that blood pressure levels for women
have the same variation as those for men.

2

DOCUMENT INFO
Shared By:
Categories:
Stats:
 views: 277 posted: 1/20/2010 language: English pages: 2