In a Normal Distribution, 99% of the Measurements Fall Within

Question

In a normal distribution, 99% of the measurements fall within _____ of the mean.
A)1%
B)5%
C)plus or minus 1 standard deviation
D)plus or minus 2 standard deviations
E)plus or minus 3 standard deviations

Accepted Answer

In a normal distribution, 99% of the measurements fall within plus or minus 3 standard deviations of the mean. This is a rule of thumb known as the empirical rule or the 68-95-99.7 rule.