Question

In a study of 82 video game players, the researchers found that the ages of these players were normally distributed, with a mean age of 17 years and a standard deviation of 3 years. determine the likely number of possible players in this study over the age of 20.

a. 15
b. 20
c. 14
d. 13

Answer 1

The normal distribution of this problem is shown below

We first need to standardise the value of X=20


`z= (20-17)/(3)=1`

Reading from the z-table, the probability of z-score 1 is 0.8413

This reading is for the area to the left of z=1.
The area to the right of z=1 is then 1-0.8413=0.1387
The probability of player over 20 years of age is 0.1387
Of 82 video game players, there is a possibility of 0.1387×82=13 possible player