Download 10 Questions on Hypothesis Testing - Homework 6 | PSY 230 and more Assignments Statistics in PDF only on Docsity! Okun NAME:_________________________ Homework Assignment #6: Hypothesis Testing 1 [C]. Match each of the outcomes of hypothesis testing--(a) correct acceptance; (b) Type II error; (c) Type I error; and (d) correct rejection--with the following scenarios: _____ Scenario I. The researcher rejects a true null hypothesis. _____ Scenario II. The researcher rejects a false null hypothesis. _____ Scenario III. The researcher retains a true null hypothesis. _____ Scenario IV. The researcher retains a false null hypothesis. 2 [C]. Suppose you set alpha at .05 and power equals .70. What is the probability associated with each outcome of hypothesis testing? ___ retaining a true null hypothesis? ___ rejecting a true null hypothesis? ___ retaining a false null hypothesis? ___ rejecting a false null hypothesis? 3 [C]. Suppose you change your mind about alpha and decide to set it at .01. What is the probability that you will retain a true null hypothesis? ___ What is the probability that you will reject a true null hypothesis? ___ Has the probability that you will retain a false null hypothesis gone up, gone down, or remained the same? ____________ Has the probability that you will reject a false null hypothesis gone up, gone down, or remained the same? ____________ 4 [C]. Smedley Trueblood wants to avoid TYPE I errors so he decides to set alpha at .001. What is the problem with doing this? 1 5 [O]. A university has developed a series of advertisements designed to keep incoming freshman exercising. Previous surveys indicate that only 50% of freshman at the university continue to exercise. To test the effectiveness of the advertising campaign, 196 freshmen who exercised during the past year receive the series of advertisements. One-hundred-and-ten of the students in the sample continue to exercise. A. What are the null and alternative hypotheses? B. Using alpha = .05, what are the critical values? C. What is the sample p? D. What is p? E. What decision should be made regarding the null hypothesis? F. Given your decision with respect to the null hypothesis, what type of error may you have made?____________ G. Do the advertisements have a significant (p < .05) effect on maintenance of exercise among freshmen? H. How much power did the researcher have if alpha = .05 and he anticipated that the advertisement would have a small effect (i.e., A = .55)? I. What sample size did the researcher need to achieve power of .80 with alpha = .05 and A = .55? 2
