Recall the data from the Physicians’ Health Study: Of the 11,034 physicians who took the placebo, 138 developed ulcers during the study. Of the 11,037 physicians who took aspirin, 169 developed ulcers.
a. Define the parameters of interest. Assign symbols to these parameters.
b. State the appropriate null and alternative hypotheses in symbols.
c. Explain why it would be okay to use the theory-based method (that is, normal distribution based method) to find a confidence interval for this study.
d. Use an appropriate applet to find and report the theory-based 95% confidence interval.
e. Does the 95% confidence interval contain 0? Were you expecting this? Explain your reasoning.
f. Interpret the 95% confidence interval in the context of the study.
g. Use the 95% confidence interval to state a conclusion about the strength of evidence in the context of the study.

h. Relatively speaking, is the 95% confidence interval narrow or wide? Explain why that makes sense.