The life X of the wing spar of a certain airplane is normally distributed with a mean of 20,000 hours of flight time and a standard deviation of 1800 hours of flight time. 

(a) Calculate the s-score of a wing spar life of 22,000 hours
(b) Calculate the probability that the life of a wing spar is less than 21,000 hours
(c) How likely is it that the life of a wing spar will be greater than 18,500 hours
(d) Calculate the 90th percentile of wing spar lives.

Answer rating: 100% (QA)

X 20000 40 Z con z XA 6 P PZ P x1 20000 1860 P 3 OF 22000 hours P X ... View the full answer