A corporation has 272 accounts receivable in a particular
category. A random sample of 50 of them was taken. The sample mean
was $492.36, and the sample standard deviation was
$149.92.
a. Find a 99% confidence interval for the population mean value
of these accounts receivable.
b. Find a 95% confidence interval for the total value of these
accounts receivable.
c. Without doing the calculations, state whether a 90%
confidence interval for the population total would be wider or
narrower than the interval found in part b