Answer: The percent higher is 41.68%. If 49 planes were selected, 20 of them should be above 15 years.
To find the percent, we first need the z-score.
(15 - 13.5) / 7.3 = 0.21
Now, use a normal distribution table to find the percent above a score of 0.21. It will be 41.68%.
To find the number of 49 planes above this value, multiply 49 by 0.4168. You will have about 20.4 planes.
A + C = 90/190
B + D = 100/190
Therefore answer is H
Answer:
439.6 inches
Step-by-step explanation:
The distance apart cna be obtained using the formular :
Number of revolutions = 7
Diameter, d = 20 inches
π * number of revolutions * diameter
3.14 * 7 * 20
= 439.6 inches
