Field results of the engines in problem #4 above report of failures at the following number of miles:

Miles

Median Rank %

57,000

15.9

162,000

38.6

330,000

630,000

61.4

1. Is the accelerated test a valid indicator of field performance? Why/why not? (2 points)

2. What % of the engines would have failed by 100,000 miles in the field? (2 points)

3. What is the average life of this engine in: (2 points)

84.1

1. 1.) Field miles?

2. 2.) Test hours?

Note: The reference answers of B, C1) and C2) are 26%, 240000, and 13, respectively. Due to manual plotting on a relatively low resolution paper, your results may be a bit different, which is fine.