CR10.16 The same survey referenced in the previous exercise reported that for a random sample of 676 parents of Canadian teens, the mean number of hours parents thought their teens spent online was 6.5 and the sample standard deviation was 8.6.

a. Do the sample data provide convincing evidence that the mean number of hours that parents think their teens spend online is less than 10 hours per week?

b. Write a few sentences commenting on the results of the test in Part

(a) and of the test in Part

(b) of the previous exercise.