Answer : 0.0129
Step-by-step explanation:
Given : Based on FAA estimates the average age of the fleets of the 10 largest U.S. commercial passenger carriers is
years and standard deviation is
years.
Sample size : 
Let X be the random variable that represents the age of fleets.
We assume that the ages of the fleets of the 10 largest U.S. commercial passenger carriers are normally distributed.
For z-score,

For x=14

By using the standard normal distribution table , the probability that the average age of these 40 airplanes is at least 14 years old will be :-

Hence, the required probability = 0.0129
If

then

The ODE in terms of these series is



We can solve the recurrence exactly by substitution:


So the ODE has solution

which you may recognize as the power series of the exponential function. Then

Answer:
57.14
Step-by-step explanation:
8/14 =x/100
cross multiply
800= 14x
x=57.1428