Suppose that a histogram of a data set is approximately symm

Suppose that a histogram of a data set is approximately symmetric and \"bell shaped\". Approximately what percent of the observations are within two standard deviations of the mean?

Solution

This is approximately normally distributed then.

By empirical rule, within 2 standard devations from the mean is around 95% of the data.   

[ANSWER, ABOUT 95%, or more exactly, 95.45%]