CR10.15 A survey of teenagers and parents in Canada conducted by the polling organization Ipsos (“Untangling the Web: The Facts About Kids and the Internet,” January 25, 2006) included questions about Internet use. It was reported that for a sample of 534 randomly selected teens, the mean number of hours per week spent online was 14.6 and the standard deviation was 11.6.

a. What does the large standard deviation, 11.6 hours, tell you about the distribution of online times for this sample of teens?

b. Do the sample data provide convincing evidence that the mean number of hours that teens spend online is greater than 10 hours per week?