In order to determine how many hours per week freshmen college students watch online news and video, a random sample of 25 students was selected. It was determined that the students in the sample spent an average of 20.5 hours with a sample standard deviation of 3.5 hours watching TV per week. Please answer the following questions:

(a)	Provide a 95% confidence interval estimate for the average number of hours that all college freshmen spend watching online news and video per week.
(b)	Assume that a sample of 31 students was selected (with the same mean and the sample standard deviation). Provide a 95% confidence interval estimate for the average number of hours that all college freshmen spend watching online news and video per week.