It is argued by a large department at a university that its class sizes in its senior undergraduate courses is increasing over time. The following are the class sizes of five randomly selected senior...

It is argued by a large department at a university that its class

sizes in its senior undergraduate courses is increasing over time.

The following are the class sizes of five randomly selected senior

classes in each of four years.

(a) Use the analysis of variance technique to test the null

hypothesis of equal average class size in these 4 years

(a = 0.05).

(b) Use the appropriate contrast to test the hypothesis that

class sizes in 1974 and 1977 are the same on the average

versus the alternative that they have increased.