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
52.8
43.2
46.0
34.3
45.0
30.6
46.8
37.8
49.5
43.0
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.)
sample mean$____thousand
sample standard deviation$____ thousand
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.)
sample mean $____thousand
sample standard deviation $____thousand
(b) What is the point estimate (in thousand dollars) of the
difference between the two population means? (Use
Private − Public.)
$____ thousand
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. (Use Private − Public. Round your
answers to one decimal place.) $____thousand to $____thousand
(Using excel)