Use the 68-95-99.7 rule to solve the problem.
-Assume that a distribution has a mean of 26 and a standard deviation of 7. What percentage of the values in the distribution do we expect to fall between 26 and 40?
A)47.5%
B)25%
C)5%
D)95%

Question

Quizplus · Accepted Answer

First, calculate the number of standard deviations 40 is from the mean (26). 40 - 26 = 14, which is 2 standard deviations away (14/7 = 2). According to the 68-95-99.7 rule, 95% of values fall within 2 standard deviations of the mean, but since we're only looking from the mean to 2 standard deviations above it, we take half of 95%, which is 47.5%.

Use the 68-95-99.7 Rule to Solve the Problem