Question

. In order to compare the life expectancies of three different brands of printers, four printers (sample size) of each brand were randomly selected. Information regarding the three brands is shown below. (60 points)

	Brand A	Brand B	Brand C
Sample mean: Average life (in months)	62	50	58
Sample variance	36	25	32

a) State the null and alternative hypotheses to be tested. (10 points)

b) Complete ANOVA table below. The null hypothesis is to be tested at 95% confidence. You need to show the entire calculation process to get full credits. What do you conclude? (50 points)

SSTR =

MSTR =

SSE =

MSE =

F =

Critical value of F =

Summarize the final answers below.

Source of Variation	SS	df	MS	F	F critical value
Between Treatment
Within Treatment
Total

Answer 1