Question: An elementary school principal would like to know how many hours the students spend watching TV each day. A sample of n=25 children is selected and a survey is sent to each child’s parents. The results indicate an average of M=3.1 hours a day with a standard deviation of s = 3.0.

a. Make a point estimate of the mean number of hours of TV per day for the population of elementary school children.

b. Make an interval estimate of the mean so that you are 90% confident that the true mean is in your interval.