The increasing annual cost (including tuition, room, board, books, and fees) to attend college has been widely discussed (Time. com). The following random samples show the annual cost of attending private and public colleges. Data are in thousands of dollars.

Private Colleges
53.8 42.2 44.0 34.3 44.0
31.6 45.8 38.8 50.5 42.0

Public Colleges
20.3 22.0 28.2 15.6 24.1 28.5
22.8 25.8 18.5 25.6 14.4 21.8

(a) Compute the sample mean (in thousand dollars) and sample standard deviation (in thousand dollars) for private colleges.

(b) What is the point estimate (in thousand dollars) of the difference between the two population means?

Interpret this value in terms of the annual cost (in dollars) of attending private and public colleges.

We estimate that the mean annual cost to attend private colleges is $ more than the mean annual cost to attend public college

(c) Develop a 95% confidence interval (in thousand dollars) of the difference between the mean annual cost of attending private and public colleges.