Answer:
Step-by-step explanation:
x, height of men is N(69, 2.8)
Sample size n =150
Hence sample std dev = 
Hence Z score = 
A) Prob that a random man from 150 can fit without bending
= P(X<78) = P(Z<3.214)=1.0000
B) n =75
Sample std dev = 
P(X bar <72) = P(Z<9.28) = 1.00
C) Prob of B is more relevent because average male passengers would be more relevant than a single person
(D) The probability from part (b) is more relevant because it shows the proportion of flights where the mean height of the male passengers will be less than the door height.