## Empirical Rule and z-score Probability

Empirical Rule The Empirical Rule applies to a normal, bell-shaped curve than 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; […]

## Empirical Rule Cheat Sheet

Empirical Rule percentiles are the percentage of data below (to the left of) an x value. Use this Quick and Easy calculator to find percentiles when you are given the population mean and standard deviation and x values. In most intro stats classes, you will only be given x values whose z-scores are integers. If […]

## Empirical Rule Excel “Cheat Sheet”

Excel “Cheat Sheet” calculator for problems involving the use of the Empirical Rule to find proportions on n within lower and upper x values or percentiles for an x-value. Empirical Rule Percentiles Excel Cheat Sheet V1.03   Chebyshev’s Theorem Excel Calculator