A company claims that the mean battery life for their MP3 players is at least 30 hours.

You suspect that this claim is incorrect - to test the claim, you select a random sample of

18 MP3 players, and find that the sample has mean battery life is 28.5 hours, with a

standard deviation of 1.7 hours.

Based on this sample data, is there enough evidence at the = .01 significance level to

reject the manufacturer's claim?

a. No, because the test statistic is not in the rejection region.

b. Yes, because p = .0008 is less than the significance level.

c. No, because p = .0007 is greater than the test statistic.