Question

given the mean of a data set is 131 and the standard deviation is 8, where will about 68% of the data lie? 131 to 139 123 to 139 123 to 131

Explanation:

Step1: Recall the empirical rule

For a normal - distribution, about 68% of the data lies within 1 standard deviation of the mean.

Step2: Calculate the lower and upper bounds

The mean $\mu = 131$ and the standard deviation $\sigma=8$.
The lower bound is $\mu-\sigma=131 - 8=123$.
The upper bound is $\mu+\sigma=131 + 8=139$.

Answer:

123 to 139