Question

In one statistics course, students reported studying an average 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.)

Answer 1

The percentile is 50.80

Explanation:

Test statistic (z) = (weekly study time - average study time)/standard deviation

weekly study time = 10 hours

average study time = 9.92 hours

standard deviation = 4.54 hours

z = (10 - 9.92)/4.54 = 0.08/4.54 = 0.02 (to 2 decimal places)

Cumulative area of the test statistic is 0.5080.

Percentile = 0.5080×100 = 50.80