Imagine that two researchers independently carry out clinical trials to test the same null hypothesis, that COX-2 selective inhibitors (which are used to treat arthritis) have no effect on the risk of cardiac arrest. They use the same population for their study, but one experimenter uses a sample size of 60 participants, whereas the other uses a sample size of 100. Assume that all other aspects of the studies, including significance levels, are the same between the two studies.

a. Which study has the higher probability of a Type II error, the 60-participant study or the 100-participant study?

b. Which study has higher power?

c. Which study has the higher probability of a Type I error?

d. Should the tests be one-tailed or two-tailed? Explain.