Multiple Choice Answers

1) If a hypothesis test has a level of significance of 5%, that means if the null is true, we don’t reject it 5% of the time. A. True B. False

2) “µ = 17” is an appropriate null hypothesis. A. True B. False

3) The value that separates a rejection region from a non-rejection region is called the test statistic. A. True B. False

4) You performed a right-tailed hypothesis test and your sample gave you a test statistic in the left tail. Which of the following is considered the appropriate next step in this test? A. Change the direction of the hypothesis. B. Change the level of significance of your test. C. Change the sample and do the test again. D. Fail to reject the null.

5) We have created a 95% confidence interval for µ with the result [10, 15]. What conclusion will we make if we test H0: µ = 16 versus H1: µ ? 16 at a = 0.05? A. Fail to reject the null. B. Reject the null and conclude the alternative. C. We cannot tell what our decisions will be from the information. D. Accept the null.

6) A statistician was setting up a hypothesis test with a level of significance dictated by upper management. However, she was concerned that the test she wished to perform might have unacceptable large possibilities of Type II error, ß. Which of the following would solve this problem? A. Convince upper management to use a larger sample. B. Convince upper management to use a smaller p-value. C. Convince upper management to reduce the level of significance of the test. D. Convince upper management to use a larger p-value.

7) The pooled variance of the two samples is the average of the sample variances when n1 = n2. A. True B. False

8) Testing the difference of means of independent samples must always be a two-tailed test. A. True B. False

9) 100 women were polled and 60 reported successfully communicating an automobile problem to an auto repairman. A sample of 150 men had 95 reporting the same success. The value of the test statistic for a test of the equality of proportions is A. 0.7293. B. -0.419. C. 0.2702. D. -0.5319.