**Empirical Rule**

The **Empirical Rule** applies to a normal, bell-shaped curve which is symmetrical about the mean. It states that within one standard deviation of the mean (both left-side and right-side) there is __about__ 68% of the data; within two standard deviations of the mean (both left-side and right-side) there is __about __95% of the data; and within three standard deviations of the mean (both left-side and right-side) there is __about__ 99.7% of the data.