Baggage fees: An airline charges the following baggage fees: $30 for the first bag and $40 for the second. Suppose 52% of passengers have no checked luggage, 30% have only one piece of checked luggage and 18% have two pieces. We suppose a negligible portion of people check more than two bags. (a) Build a probability model, compute the average revenue per passenger, and compute the corresponding standard deviation.
(b) About how much revenue should the airline expect for a flight of 120 passengers? With what standard deviation?