In an advertising study done for Milestone magazine, a random sample of Milestone subscribers was selected. Each subscriber in the sample was asked to recall advertisements in this month’s edition of the magazine. The average number of advertisements recalled by sample members was 8.2, with a sample standard deviation of 3.6. Show the appropriate 95% confidence interval for the population of Milestone subscribers if the size of the sample is
a. 15
b. 25
c. 150