A comprehensive trial investigating the relationship between vitamin E supplementation and reduced risk for prostate cancer was carried out across the US. Suppose the trial reported that among the 648 patients receiving the supplement program, 267 developed prostate cancer, while only 212 of the 711 patients without the supplementation developed the disease.

A)Calculate a risk difference between the two groups for developing prostate cancer.

B)Construct a 95% confidence interval for your estimate calculated above.

C)Carry out a formal test to determine if there is a significant difference in the risk for developing prostate cancer among the two groups. Write out your null and alternative hypotheses and use an alpha level of 0.05.

D)Comment on the effectiveness of the supplementation at reducing prostate cancer. What did you find relevant to the research hypothesis?