Question 1
An engineer is going to redesign an ejection seat for an airplane. The seat was was designed for pilots between 120 lb and 171 lb. The new population of pilots has normally distributed weights with a mean of 129 lb and a standard deviation of 30.8 lb.
a. if a pilot is randomly selected, find the probability that the weight is between 120 lb and 171 lb.
round to four decimal places
P(120 < X < 171) = P( (120-129)/30.8 < z < (171-129)/30.8) = P( -0.29 < z < 1.36)= P( z < 1.36 ) – P( z -0.29)= 0.9131 – 0.3859= 0.5272
