The probability mass between two standard deviations around the mean for a normal distribution is:
A)66%
B)90%
C)75%
D)95%
E)50%

Question

Quizplus · Accepted Answer

The area between two standard deviations around the mean for a normal distribution is approximately 95%. This is a well-known empirical rule called the 68-95-99.7 rule, which states that for a normal distribution, approximately 68% of the data fall within one standard deviation of the mean, approximately 95% within two standard deviations, and approximately 99.7% within three standard deviations. Therefore, choice D is correct, as it gives the closest probability to the correct answer.

The Probability Mass Between Two Standard Deviations Around the Mean