Allegiant Airlines charges a mean base fare of $89. In addition, the airline charges for mak- ing a reservation on its website, checking bags, and inflight beverages. These additional charges average $39 per passenger (Bloomberg Businessweek, October 8-14, 2012). Sup- pose a random sample of 60 passengers is taken to determine the total cost of their flight on Allegiant Airlines. The population standard deviation of total flight cost is known to be $40.

1. What is the population mean cost per flight?
2. What is the probability the sample mean will be within $10 of the population mean cost per flight?
3. What is the probability the sample mean will be within $5 of the population mean cost per flight?