Empirical Rule: Definition, Formula, Example, How It's Used

The empirical rule, also known as the 68-95-99.7 rule or the normal distribution, is a statistical principle that describes the distribution of data. It states that for a normal distribution, approximately 68% of the data will fall within one standard deviation of the mean, 95% will fall within two standard deviations of the mean, and 99.7% will fall within three standard deviations of the mean.

The empirical rule can be used to make inferences about the probability of an event occurring. For example, if a normal distribution has a mean of 100 and a standard deviation of 10, then we can say that there is a 68% chance that a randomly selected value will be between 90 and 110.

The empirical rule is a useful tool for understanding the distribution of data and making inferences about the probability of an event occurring.