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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 C. errors cannot be made 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, what decision should be made? 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, what decision should be made? 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, Inc. (CMI) advises e-commerce businesses on their marketing strategies. Addalie McMinn, VP of Research at CMI, expects increasingly intense competition between online brokerages for new customers as the industry matures. She wants to learn more about the customers of online brokerages; she 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 as an address book, a calendar service, and links to favorite web sites for gifts. Should Addalie segment the customer population? Are all factors equally important for all market segments? Does age matter? Does gender matter? Does profession matter? Addalie has accumulated an extensive database of on traditional full-service brokerage customers. She plans to use summary measures from the database as benchmarks for comparisons with online customers. Describe the statistical methods that will be useful to Addalie during the study. M BApp 302 Test Bank