A camp director is interested in the mean number of letters each child sends during his or her camp session. The population standard deviation is known to be 2.5. A survey of 20 campers is taken. The...

A camp director is interested in the mean number of letters each child sends during his or
her camp session. The population standard deviation is known to be 2.5. A survey of 20
campers is taken. The mean from the sample is 7.9 with a sample standard deviation of 2.8.
Construct a 90% confidence interval for the population mean number of letters campers
send home. What will happen to the error bound and confidence interval if 500 campers are
surveyed?