A random sample of eight customers was interviewed in order to find the number of personal computers they planned to order next year. The results were 22, 18, 24, 47, 64, 32, 45, and 35. You are interested in knowing about the larger population that these customers represent.
a. Find the usual summary measure of the variability of individuals.
b. Approximately how far is the sample average from the population mean?
c. Find the 95% confidence interval for the population mean.
d. Find the 99% confidence interval for the population mean.