A

consumer report company records the monthly cell phone bills of students at Bush Campus and takes a random sample of 10 cell phone bills from

provider AG & G and another of 8 cell phones bills from provider CT&T that reside in the Bush campus. The summary data is given bellow. We want to compare the mean cost between CT&T and AG & G phones. Are they the same? It is assumed that the populations are normal, and the variances are approximately equal and alpha = 0.05. Which hypothesis test is appropriate? What kind of alternative should be used?

Perform the test and discuss the conclusion.

Sample Mean SD Sample size

AG&G $43 7 10

CT&T $50 11 8

--. Does the data suggest that the standard deviation of the AG&G bills is smaller than that for CT&T bills? Carry out a test at significance level 0.01