Approximately how many students will typically get scores within one standard deviation of the mean either above or below the mean)on a standardized achievement test?
A)About two-thirds of them
B)About one-third of them
C)About 20% of them
D)About half of them

Question

Quizplus · Accepted Answer

By definition, one standard deviation above and below the mean covers about 68% of the distribution. Therefore, approximately two-thirds of students will get scores within one standard deviation of the mean.

Approximately How Many Students Will Typically Get Scores Within One