Question

Scores on a standardized military exam are normally distributed with a mean of 57 and a standard deviation of 9. Consider a group of 4000 military students. Approximately how many students will score less than 66 on the test?

Answer 1

Use the formula:

66-57=9 (66 minus the mean of 57)

9/9 = 1 (standard deviation divided by 9)

Find 1 on a Z-Score table. This equals .8413

.8413(4000) = 3,365.2 (Z-Score multiplied by the number of total students)

Can also be 3,366 ;)