Chapter 8.4, Problem 8E

Testing the Difference Between Two Proportions In Exercises 7–12, (a) identify the claim and state H₀ and H_α, (b) find the critical value(s) and identify the rejection region(s), (c) find the standardized test statistic z. (d) decide whether to reject or fail to reject the null hypothesis, and (e) interpret the decision in the context of the original claim. Assume the samples are random and independent.

8. Cancer Drug In a study, 760 men with recurrent prostate cancer underwent radiation with or without a type of hormone-based chemotherapy. For 24 months, 384 subjects were given the chemotherapy and 376 subjects were given a placebo. The numbers who survived and did not survive after 12 years were tracked. The results are shown at the left. At α = 0.10, can you support the claim that the proportion of 12-year survivors is greater for subjects who were given the chemotherapy than for subjects who were given the placebo? (Adapted from The New England Journal of Medicine)

FIGURE FOR EXERCISE 8