a. A personality theorist expects that two particular traits have a linear correlation on the order of .40 in the population she plans to sample. She wishes to test the null hypothesis that the correlation between the two traits is exactly zero, using the .05 criterion of significance and a random sample of 65 subjects. Is the power of this statistical test satisfactory? Explain.

b. How large a sample would the theorist in part (a) need to obtain power = .9 with alpha set at .01 for a twotailed test? For a one-tailed test?