Question

A Consumer Reports study in February of 2010 found the iPhone customers use an average of 270 megabytes of data per month. Prior to the release of the iPhone 4 during summer
of 2010, AT&T was concerned that the average date usage per customer would increase.
A random sample of 38 iPhone customers was selected and it found that the average use per month was 295 megabytes with a sample standard deviation of 75 megabytes.

a. State the null and alternative hypothesis
b. Using α = .05, is there enough evidence from this sample for AT&T to conclude

that the data usage per customer increased following the release of the iPhone 4? c. Compute the p-value.
d. Repeat the preceding hypothesis test using the critical value approach

e. Add bell curve graph

Answer 1