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
Answer:
19/20
Step-by-step explanation:
write all numerators above the common denominator 20
14+5/20
19/20
The values of a and b are 1/4 and 1/5 respectively
<h3>How to determine the true statement?</h3>
The function is given as:
16x^2 - 25y^2 = 1
The above function is a horizontal hyperbola.
A horizontal hyperbola that passes through the origin is represented as:

Rewrite 16x^2 - 25y^2 = 1 as

By comparison, we have:


Solve for a and b


Hence, the values of a and b are 1/4 and 1/5 respectively
Read more about hyperbola at:
brainly.com/question/27799190
#SPJ1
Answer:
7
Step-by-step explanation:
Working backwards:
19 + 9 = 28
28/ 4 = 7
Checking work:
7 x 4 = 28
28 - 9 = 19