arithmetic mean (average)
The sum of a series of observations divided by the number of observations. Symbol: x(bar). It can be calculated by the formula: \[\bar{x}=\frac{\sum x_{i}}{n}\]
All summations are taken from 1 to \(n\). Note that the arithmetic mean is an unbiased estimate of the population mean, i.e. \(\mu\) is the limiting value for \(\bar{x}\), as \(n\rightarrow \infty\).
PAC, 1994, 66, 595. 'Nomenclature for the presentation of results of chemical analysis (IUPAC Recommendations 1994)' on page 599 (