An engineer is going to redesign an ejection seat for an airplane. The seat was
ID: 3069215 • Letter: A
Question
An engineer is going to redesign an ejection seat for an airplane. The seat was designed for weights between 130 and 181 lbs. The new pilots have normally distributed weights with a man of 136 and a standard deviation of 26.5 If 30 different pilots are randomly selected, find the probability that their mean weight is between 130 and 181An engineer is going to redesign an ejection seat for an airplane. The seat was designed for weights between 130 and 181 lbs. The new pilots have normally distributed weights with a man of 136 and a standard deviation of 26.5 If 30 different pilots are randomly selected, find the probability that their mean weight is between 130 and 181
Explanation / Answer
Solution:
Given in the question
Mean =136
Standard deviation = 26.5
We need to calculate P(130<Xbar<181) =p(xbar<181)-p(xbar<130)
Z = (130-136)/26.5/sqrt(30) = -1.2399
Z = (181-136)/26.5/sqrt(30) = 9.299
So from z table we can find p- value correspond to Z value
P(130<xbar<181) = 0.9999- 0.1075= 0.8924
So there is 89.24% chances to find their mean weight is between 130 and 181.