Previously, an organization reported that teenagers spent an average of4.5 hours per week on the phone. The organization thinks that the currentmean is higher.

To test the claim,fifteen randomly chosen teenagers were asked how many hours per week they spend on the phone. The sample mean was 4.75 hours with a sample standard deviation of 2.0.

Suppose that a hypothesis test is conducted to test the claim that the mean hours is more than 4.5 hours per week. What are the hypotheses for the test?

a. Ho: > 4.5 Ha: < 4.5

b. Ho: < 4.5 Ha: > 4.5

c. Ho: > 4.5 Ha: < 4.5

d. Ho: = 4.5 Ha: 4.5