According to the Air Transport Association of America, the average operating cost of an MD-80 jet airliner is $2,270 per hour. Suppose the operating costs of an MD-80 jet airliner are normally distributed with a standard deviation of $173 per hour. (Round the value of z to 2 decimal ploces, eg. 1.25. Round your answers to 2 decimal places, eg. 125.31.) (a) At what operating cost would only 20% of the operating costs be less? 5 (b) At what operating cost would 65% of the operating costs be more? 3 (c) What operating cost would be more than 85% of operating costs?.

1. According to the Air Transport Association of America, the average operating cost of an MD-80
jet airliner is $2,270 per hour. Suppose the operating costs of an MD-80 jet airliner are normally
distributed with a standard deviation of $173 per hour. (Round the value of z to 2 decimal ploces,
eg. 1.25. Round your answers to 2 decimal places, eg. 125.31.) (a) At what operating cost would
only 20% of the operating costs be less? 5 (b) At what operating cost would 65% of the operating
costs be more? 3 (c) What operating cost would be more than 85% of operating costs?