The following data represent the 5-year rate of return (in percent) for a random sample of stocks in financial services and an independent random sample of stocks in health care

(a) Has there been a difference in the rate of return of companies in the Financial Services sector versus those in the Health Care sector over the past 5 years? Use an α = 0.05 level of significance.
(b) Is there a difference in the standard deviation rate of return between the two sectors? Remember, standard deviation is a measure of risk in equities.