Question

If the mean of an exam is 76 and standard deviation is 9, what is the probability that anyone scored 100

Answer 1

Below

Explanation:

100 pts is 24 points above the mean

24 / 9 = 2.666 standard deviations ABOVE the mean

z-score = 2.666

from z-score table , this corresponds to .9961 people scoring less than 100 ....or 1 - .9961 = .0039 scoring 100 (.39 %)