# Arithmetic Mean

## Description

Arithmetic mean is the sum of a collection of numbers divided by the number of numbers in the collection. The collection is often a set of results of an experiment, or a set of results from a survey. The arithmetic mean is the measure of the central tendency of a probability distribution or of the random variable characterized by that distribution. If the arithmetic mean of a population of numbers is desired, then the estimate of it that is unbiased is the arithmetic mean of a sample drawn from the population. (In statistics, the bias (or bias function) of an estimator is the difference between this estimator’s expected value and the true value of the parameter being estimated. An estimator or decision rule with zero bias is called unbiased.)

Related formulas## Variables

X | Arithmetic Mean (dimensionless) |

x | Set of numbers (dimensionless) |