The increasing annual cost (including tuition, room, board, books, and fees) to attend college has been widely discussed (Time.c
om). 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. (Round the standard deviation to two decimal places.)
(b) Compute the sample mean (in thousand dollars) and sample standard deviation (in thousand dollars) for public colleges. (Round the standard deviation to two decimal places.)
(c) What is the point estimate (in thousand dollars) of the difference between the two population means? (Use Private − Public.)
We estimate that the mean annual cost to attend private colleges is $ more than the mean annual cost to attend public college
(d) Develop a 95% confidence interval (in thousand dollars) of the difference between the mean annual cost of attending private and public colleges. (Use Private − Public. Round your answers to one decimal place.)
