Answer: 0.4758
Step-by-step explanation:
Given : Mean : 
Standard deviation : 
Also, the new population of pilots has normally distributed .
The formula to calculate the z-score :-
For x=130 lb .
For x=171lb.
The p-value =
Hence, the required probability : 0.4758
Set up a proportion
EA / EB = ED/ EC
16 / (5x + 2 + 16) = 12 / (12 + 24)
16/(5x + 18) = 12 / 36 Cross multiply
16 * 36 = (4x + 18)*12 Remove the brackets
576 = 48x + 216 Subtract 216 from both sides.
360 = 48x Divide by 48
360/48 = x
7.5 = x
131.818182% and can round to 131.82
Remember that 45%=45/100=0.45
So if the tennis player serves the ball 300 times, and 45% cannot be returned, then we can use the following expression to solve for the answer:
300*0.45=135serves
Answer: 135 serves will not be returned
