Calculate the statistical power of the hypothesis test you carried in part awhen you tested whether aspirin had different rate of strokes compared to the placebo group.

To compute the power, assume the true relative risk of developing a stroke while taking a daily aspirin compared to placebo is 3.0 (which is approximately the observed effect size). Assume the baseline proportion of strokes in this population is 2/10,000.

Answer: ________________

Use the following SAS program shell - but you will need fill in the blanks-

proc power;

twosamplefreq test=pchi

alpha=_____________

sides=_____________

relativerisk = _____________

refproportion = _____________

ntotal = 22071

power = .;

run;

a)(4 points) Interpret the power you calculated using SAS and comment what it might imply about your findings. (Hint: review discussion article from week 8: Commentary: Not Enough Patients?)