A variety of routine maintenance checks are made on commercial airplanes prior t

ID: 2623808 • Letter: A

Question

A variety of routine maintenance checks are made on commercial airplanes prior to each takeoff. A particular maintenance check of an airplane's landing gear requires an average of 15 minutes of a maintenance engineer's time. In fact, the exact time required is normally distributed with a mean of 15 minutes and a standard deviation of 3 minutes. As part of a larger simulation model designed to determine total on-ground maintenance time for an airplane, we will need to simulate the actual time required to perform this maintenance check on the airplane's landing gear. Using random numbers of 0.1221, 0.9659, 0.3684, 0.5145, and 0.7807, compute the time required for each of five simulated maintenance checks of the airplane's landing gear.

If required, round your answers to two decimal places.

Random Number Time required 0.1221 min 0.9659 min 0.3684 min 0.5145 min 0.7807 min

Explanation / Answer

Observe the values to calculate the time required for maintenance checks as follows:

Average time required for check is 15 minutes.

Standard deviation for the check is 3 minutes.

Observe the following formula to calculate the time

Time = a+r(b-a)

Where:

A is average time.

B is the standard deviation.

Therefore the equation is:

Time = 3+r(15-3)

= 3+12r

Substitute the value of r as the random numbers:

T1=3+0.1221*12 = 4.4652

T2=3+0.9659*12 = 14.5908

T3=3+0.3684*12 = 7.4208

T4=3+0.5145*12 = 9.174

T5=3+0.7807*12 = 12.3684

Random number

Time required

0.1221

4.46

0.9659

14.59

0.3684

7.42

0.5145

9.17

0.7807

12.36