Question

In one statistics course, students reported studying an average (mean) of 9.92 hours a week, with a standard deviation of 4.54. Treating the class as the population, what is the percentile for a student in the class who studies 10 hours a week? (Round z score to two decimal places before looking up the percentile.)

Answer 1

For the student who is studying 10 hours a week is in the 57.93th percentile.

Explanation:

Corresponding z-score for the student who studies 10 hours a week can be calculated by the formula

z=
`(x-M)/(s)` where

• x is the hours student work in a week, which is 10,
• M is the mean studying hour of the class, which is 9.92,
• s is the standart deviation which is 4.54

from here we find that z=
`(10-9.92)/(4.54)`≈0.2

Corresponding percentile for z=0.2 is 57.93