The following list is a sampling of the costs of various statistics textbooks used at several colleges. Give the upper confidence limit for a 95% confidence interval estimate for the mean cost of all statistics textbooks.

Question

109.95; 92.00; 96.70; 84.85; 92.60; 84.45; 90.95; 77.00; 75.50

Answer 1

Formula:

CI95 = mean ± 1.96(sd/√n)

You will need to calculate the mean and standard deviation for your data. In the formula, n = sample size.

Once you have what you need, substitute into the formula and determine the confidence interval.

I hope this will help get you started.

Answer 2

28.22