MGMT208 CH 9

A survey claims that 9 out of 10 doctors recommend aspirin for their patients with headaches. To test this claim against the alternative that the actual proportion of doctors who recommend aspirin is less than 0.90, a random sample of 100 doctors was selected. Suppose that the test statistic is -2.20. Can you conclude that H0 should be rejected at the (a) α = 0.10, (b) α = 0.05, and (c) α = 0.01 level of Type I error? a) (a) yes; (b) yes; (c) no b) (a) no; (b) no; (c) yes c) (a) yes; (b) yes; (c) yes d) (a) no; (b) no; (c) no

a) (a) yes; (b) yes; (c) no

A major DVD rental chain is considering opening a new store in an area that currently does not have any such stores. The chain will open if there is evidence that more than 5,000 of the 20,000 households in the area are equipped with DVD players. It conducts a telephone poll of 300 randomly selected households in the area and finds that 96 have DVD players. The value of the test statistic in this problem is approximately equal to ________. a) 2.80 b) 1.30 c) 2.60 d) 1.94

a) 2.80

A major DVD rental chain is considering opening a new store in an area that currently does not have any such stores. The chain will open if there is evidence that more than 5,000 of the 20,000 households in the area are equipped with DVD players. It conducts a telephone poll of 300 randomly selected households in the area and finds that 96 have DVD players. State the test of hypothesis that is of interest to the rental chain. a) H0: π ≤ 0.25 versus H1: π > 0.25 b) H0: π ≤ 0.32 versus H1: π > 0.32 c) H0: μ ≤ 5,000 versus H1: μ > 5,000 d) H0: π ≤ 5,000 versus H1: μ > 5,000

a) H0: π ≤ 0.25 versus H1: π > 0.25

How many tissues should the Kimberly Clark Corporation package of Kleenex® contain? Researchers determined that 60 tissues is the mean number of tissues used during a cold. Suppose a random sample of 100 Kleenex users yielded the following data on the number of tissues used during a cold: = 52, S = 22. Suppose the alternative you wanted to test was H1: μ < 60. State the correct rejection region for α = 0.05. a) Reject H0 if t < -1.6604. b) Reject H0 if t > 1.6604. c) Reject H0 if t < -1.9842. d) Reject H0 if t > 1.9842 or Z < -1.9842.

a) Reject H0 if t < -1.6604.

Which of the following would be an appropriate null hypothesis? a) The population proportion is not less than 0.65. b) The sample proportion is no less than 0.65. c) The population proportion is less than 0.65. d) The sample proportion is less than 0.65.

a) The population proportion is not less than 0.65.

A survey claims that 9 out of 10 doctors recommend aspirin for their patients with headaches. To test this claim against the alternative that the actual proportion of doctors who recommend aspirin is less than 0.90, a random sample of 100 doctors results in 83 who indicate that they recommend aspirin. The value of the test statistic in this problem is approximately equal to ________. a) -4.12 b) -2.33 c) -0.07 d) -1.86

b) -2.33

How many tissues should the Kimberly Clark Corporation package of Kleenex® contain? Researchers determined that 60 tissues is the mean number of tissues used during a cold. Suppose a random sample of 100 Kleenex users yielded the following data on the number of tissues used during a cold: = 52, S = 22. Suppose the test statistic does fall in the rejection region at α = 0.05. Which of the following conclusions is correct? a) At α = 0.05, there is insufficient evidence to conclude that the mean number of tissues used during a cold is not 60 tissues. b) At α = 0.10, there is sufficient evidence to conclude that the mean number of tissues used during a cold is not 60 tissues. c) At α = 0.05, there is not sufficient evidence to conclude that the mean number of tissues used during a cold is 60 tissues. d) At α = 0.05, there is sufficient evidence to conclude that the mean number of tissues used during a cold is 60 tissues.

b) At α = 0.10, there is sufficient evidence to conclude that the mean number of tissues used during a cold is not 60 tissues.

Which of the following would be an appropriate alternative hypothesis? a) The mean of a sample is greater than 55. b) The mean of a population is greater than 55. c) The mean of a sample is equal to 55. d) The mean of a population is equal to 55.

b) The mean of a population is greater than 55.

If an economist wishes to determine whether there is evidence that mean family income in a community equals $50,000, a) either a one-tail or two-tail test could be used with equivalent results. b) a two-tail test should be utilized. c) a one-tail test should be utilized. d) none of the above

b) a two-tail test should be utilized.

A Type II error is committed when a) you reject a null hypothesis that is true. b) you don't reject a null hypothesis that is false. c) you don't reject a null hypothesis that is true. d) you reject a null hypothesis that is false.

b) you don't reject a null hypothesis that is false.

A major DVD rental chain is considering opening a new store in an area that currently does not have any such stores. The chain will open if there is evidence that more than 5,000 of the 20,000 households in the area are equipped with DVD players. It conducts a telephone poll of 300 randomly selected households in the area and finds that 96 have DVD players. The p-value associated with the test statistic in this problem is approximately equal to ________. a) 0.0051 b) 0.0100 c) 0.0026 d) 0.0013

c) 0.0026

An entrepreneur is considering the purchase of a coin-operated laundry. The current owner claims that over the past five years, the mean daily revenue was $675 with a population standard deviation of $75. A sample of 30 days reveals a daily mean revenue of $625. If you were to test the null hypothesis that the daily mean revenue was $675, which test would you use? a) t test of a population proportion b) t test of population mean c) Z test of a population mean d) Z test of a population proportion

c) Z test of a population mean

How many tissues should the Kimberly Clark Corporation package of Kleenex® contain? Researchers determined that 60 tissues is the mean number of tissues used during a cold. Suppose a random sample of 100 Kleenex users yielded the following data on the number of tissues used during a cold: = 52, S = 22. Using the sample information provided, calculate the value of the test statistic. a) t = (52 - 60) / (22/1002) b) t = (52 - 60) / (22/100) c) t = (52 - 60) / (22/10) d) t = (52 - 60) / 22

c) t = (52 - 60) / (22/10)

A manager of the credit department for an oil company would like to determine whether the mean monthly balance of credit card holders is equal to $75. An auditor selects a random sample of 100 accounts and finds that the mean owed is $83.40 with a sample standard deviation of $23.65. If you were to conduct a test to determine whether the auditor should conclude that there is evidence that the mean balance is different from $75, which test would you use? a) t test of a population proportion b) Z test of a population mean c) t test of population mean d) Z test of a population proportion

c) t test of population mean

A major DVD rental chain is considering opening a new store in an area that currently does not have any such stores. The chain will open if there is evidence that more than 5,000 of the 20,000 households in the area are equipped with DVD players. It conducts a telephone poll of 300 randomly selected households in the area and finds that 96 have DVD players. The rental chain's conclusion from the hypothesis test using a 5% level of significance is: a) not to open a new store. b) to delay opening a new store until additional evidence is collected. c) to open a new store. d) We cannot tell what the decision should be from the information given.

c) to open a new store.

A major DVD rental chain is considering opening a new store in an area that currently does not have any such stores. The chain will open if there is evidence that more than 5,000 of the 20,000 households in the area are equipped with DVD players. It conducts a telephone poll of 300 randomly selected households in the area and finds that 96 have DVD players. The decision on the hypothesis test using a 5% level of significance is: a) to fail to reject H0 in favor of H1. b) to accept H0 in favor of H1. c) to reject H0 in favor of H1. d) We cannot tell what the decision should be from the information given.

c) to reject H0 in favor of H1.

A Type I error is committed when a) you reject a null hypothesis that is false. b) you don't reject a null hypothesis that is false. c) you reject a null hypothesis that is true. d) you don't reject a null hypothesis that is true.

c) you reject a null hypothesis that is true.

How many tissues should the Kimberly Clark Corporation package of Kleenex® contain? Researchers determined that 60 tissues is the mean number of tissues used during a cold. Suppose a random sample of 100 Kleenex users yielded the following data on the number of tissues used during a cold: = 52, S = 22. Suppose the test statistic does fall in the rejection region at α = 0.05. Which of the following decisions is correct? a) At α = 0.10 you reject H0. b) At α = 0.10, you do not reject H0. c) At α = 0.05, you do not reject H0. d) At α = 0.05, you reject H0

d) At α = 0.05, you reject H0

How many tissues should the Kimberly Clark Corporation package of Kleenex® contain? Researchers determined that 60 tissues is the mean number of tissues used during a cold. Suppose a random sample of 100 Kleenex users yielded the following data on the number of tissues used during a cold: = 52, S = 22. Give the null and alternative hypotheses to determine if the number of tissues used during a cold is less than 60. a) H0: μ ≤ 60 and H1: μ > 60. b) H0: = 52 and H1: ≠ 52. c) H0: ≥ 60 and H1: < 60. d) H0: μ ≥ 60 and H1: μ < 60.

d) H0: μ ≥ 60 and H1: μ < 60.

A survey claims that 9 out of 10 doctors recommend aspirin for their patients with headaches. To test this claim against the alternative that the actual proportion of doctors who recommend aspirin is less than 0.90, a random sample of 100 doctors was selected. Suppose you reject the null hypothesis. What conclusion can you reach? a) There is sufficient evidence that the proportion of doctors who recommend aspirin is not less than 0.90. b) There is not sufficient evidence that the proportion of doctors who recommend aspirin is not less than 0.90. c) There is not sufficient evidence that the proportion of doctors who recommend aspirin is less than 0.90. d) There is sufficient evidence that the proportion of doctors who recommend aspirin is less than 0.90.

d) There is sufficient evidence that the proportion of doctors who recommend aspirin is less than 0.90.

You have created a 95% confidence interval for μ with the result 10 ≤ μ ≤ 15. What decision will you make if we test H0: μ =16 versus H1: μ ≠ 16 at α = 0.01? a) Reject Ho in favor of H1. b) Fail to reject Ho in favor of H1. c) Do not reject Ho in favor of H1. d) You cannot tell what our decision will be from the information given.

d) You cannot tell what our decision will be from the information given.

The power of a statistical test is a) the probability of rejecting H0 when it is true. b) the probability of not rejecting H0 when it is false. c) the probability of not rejecting H0 when it is true. d) the probability of rejecting H0 when it is false.

d) the probability of rejecting H0 when it is false.