Roughly all of the z-scores in the standard normal distribution are with in ______ standard deviations of the mean.
A) ±1
B) ±1.96
C) ±2
D) ±3

Question

Quizplus · Accepted Answer

In the standard normal distribution, approximately 68% of the z-scores fall within ±1 standard deviation of the mean, approximately 95% within ±2 standard deviations, and approximately 99.7% within ±3 standard deviations. Therefore, the best choice is D, ±3 standard deviations.

Roughly All of the Z-Scores in the Standard Normal Distribution