A stock analyst wondered whether the mean rate of return of financial, energy, and utility stocks differed over the past 5 years. He obtained a simple random sample of eight companies from each of the three sectors and obtained the 5-year rates of return shown in the following table (in percent).

(a) State the null and alternative hypothesis.

(b) Are the mean rates of return different at the alpha = 0.05 level of significance? Please explain your answer, citing numeric and other evidence in support of your response.

Financial	Energy	Utilities
10.76	12.72	11.88
15.05	13.91	5.86
17.01	6.43	13.46
5.07	11.19	9.9
19.05	18.79	3.95
8.16	20.73	3.44
10.38	9.6	7.11
6.75	17.4	15.7