The file titled Clothing contains the monthly retail sales ($millions) of U.S. women’s clothing stores for 70 months. A sample taken from this population to estimate the average sales in this time period follows:

2,942 2,574 2,760 2,939 2,642 2,905 2,568 2,677 2,572 3,119 2,697 2,884 2,632 2,742 2,671 2,884 2,946 2,825 2,987 2,729 2,676 2,846 3,112 2,924 2,676

a. Calculate the population mean.

b. Calculate the sample mean.

c. How much sampling error is present in this sample?

d. Determine the range of possible sampling error if 25 sales figures are sampled at random from this population.