In order to determine the average weight of carry-on luggage by passengers in airplanes, a sample of 25 pieces of carry-on luggage was collected and weighed. The average weight was 18 pounds. Assume that we know the standard deviation of the population to be 7.5 pounds.

· Determine a 97% confidence interval estimate for the mean weight of the carry-on luggage.

· Determine a 95% confidence interval estimate for the mean weight of the carry-on luggage.