arithmetic mean (average)

The sum of a series of observations divided by the number of observations. Symbol: x ̄. It can be calculated by the formula:
x ̄ = ∑ 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. μ is the limiting value for x ̄, as n → ∞.
PAC, 1994, 66, 595 (Nomenclature for the presentation of results of chemical analysis (IUPAC Recommendations 1994)) on page 599