BUS 310 Ch.9 quiz

A Type I error is committed when A. we reject a null hypothesis that is true. B. we don't reject a null hypothesis that is true. C. we reject a null hypothesis that is false. D. we don't reject a null hypothesis that is false.

A

True or False: For a given level of significance, if the sample size is increased, the power of the test will increase. A. True B. False

A

We have created a 95% confidence interval for μ with the result (10, 15). What decision will we make if we test H0: μ = 16 vs H1: μ ≠ 16 at α = 0.05? A. Reject H0 in favor of H1. B. Accept H0 in favor of H1. C. Fail to reject H0 in favor of H1. D. We cannot tell what our decision will be from the information given.

A

Which of the following would be an appropriate null hypothesis? A. The mean of a population is equal to 55. B. The mean of a sample is equal to 55. C. The mean of a population is greater than 55. D. Only (a) and (c) are true.

A

If an economist wishes to determine whether there is evidence that average family income in a community exceeds $25,000 A. either a one-tailed or two-tailed test could be used with equivalent results. B. a one-tailed test should be utilized. C. a two-tailed test should be utilized. D. None of the above.

B

The owner of a local nightclub has recently surveyed a random sample of n = 250 customers of the club. She would now like to determine whether or not the mean age of her customers is over 30. If so, she plans to alter the entertainment to appeal to an older crowd. If not, no entertainment changes will be made. The appropriate hypotheses to test are: A. H0: μ ≥ 30 versus H1:μ < 30 B. H0: μ ≤ 30 versus H1:μ > 30 C. H0: X̄ ≥ 30 versus H1: X̄ < 30 D. H0: X̄ ≤ 30 versus H1: X̄ > 30

B

A ___________ is a numerical quantity computed from the data of a sample and is used in reaching a decision on whether or not to reject the null hypothesis. A. significance level B. critical value C. test statistic

C

The power of a test is measured by its capability of A. rejecting a null hypothesis that is true. B. not rejecting a null hypothesis that is true. C. rejecting a null hypothesis that is false. D. not rejecting a null hypothesis that is false.

C

Which of the following would be an appropriate alternative hypothesis? A. The mean of a population is equal to 55. B. The mean of a sample is equal to 55. C. The mean of a population is greater than 55. D. The mean of a sample is greater than 55.

C

A Type II error is committed when A. we reject a null hypothesis that is true. B. we don't reject a null hypothesis that is true. C. we reject a null hypothesis that is false. D. we don't reject a null hypothesis that is false.

D

The value that separates a rejection region from a non-rejection region is called the {critical value}.

True

True or False: Suppose, in testing a hypothesis about a proportion, the p-value is computed to be 0.034. The null hypothesis should be rejected if the chosen level of significance is 0.01. True False

True

True or False: The smaller is the p-value, the stronger is the evidence against the null hypothesis. True False

True