Recall Exercise 5.2.4 where researchers Wilt et al. (New England Journal of Medicine, 2012) investigated whether surgery, compared to just observation, was (more) effective in improving men’s survival chances after being diagnosed with prostate cancer. The researchers identified 731 men with localized prostate cancer and randomly assigned 364 to surgery and the remaining 367 to observation. All participants were followed for about 10 years. In those 10 years, 21 surgery recipients died of prostate cancer related reasons compared to 31 observation recipients.
a. Define (in words) the parameters of interest of this study. Also, assign symbols to the parameters.

b. State the appropriate null and alternative hypotheses in words.
c. State the appropriate null and alternative hypotheses in symbols.
d. Explain why it is valid to use the theory-based approach to test the hypotheses stated above.
e. Use an appropriate applet to find a theory-based p-value to test the above hypotheses. Report the standardized statistic as well as the p-value.
f. Use an appropriate applet to find a theory-based 99% confidence interval and interpret the resulting interval in the context of the study.
g. Based on your findings, state a complete conclusion about the study. Be sure to address significance, estimation (confidence interval), causation, and generalization.

Data from exercise 5.2.4

Researchers Wilt et al. (New England Journal of Medicine, 2012) investigated whether surgery, compared to just observation, was (more) effective in improving men’s survival chances aft er being diagnosed with prostate cancer. Th e researchers identified 731 men with localized prostate cancer who volunteered to participate. They randomly assigned 364 men to surgery and the remaining 367 to observation. All participants were followed for about 10 years. In those 10 years, 21 surgery recipients died of prostate cancer related reasons compared to 31 observation recipients.