Question

According to the Air Transport Association of America, the average operating cost of an MD-80 jet airliner is $2,087 per hour. Suppose the operating costs of an MD-80 jet airliner are normally distributed with a standard deviation of $160 per hour.

(Round the value of z to 2 decimal places. Round your answers to 2 decimal places.)

(a) At what operating cost would only 23% of the operating costs be less? $ (b) At what operating cost would 65% of the operating costs be more? $ (c) What operating cost would be more than 85% of operating costs? $

Answer 1

Let X denotes the operating cost of a randomly selected MD-80 jet airliner.

Here,

X ~ Normal(2087, 160²)

a)

b)

c)