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 $177per hour.

(Round the value of z to 2 decimal places, e.g. 1.25. Round your answers to 2 decimal places, e.g. 125.31.)

(a)At what operating cost would only20% of the operating costs be less?

$

enter a dollar amount rounded to 2 decimal places

(b)At what operating cost would 65% of the operating costs be more?

$

enter a dollar amount rounded to 2 decimal places

(c)What operating cost would be more than 85% of operating costs?

$

enter a dollar amount rounded to 2 decimal places