Definition:Arithmetic Mean
This page is about Arithmetic Mean in the context of Algebra. For other uses, see Mean.
Definition
Let $x_1, x_2, \ldots, x_n \in \R$ be real numbers.
The arithmetic mean of $x_1, x_2, \ldots, x_n$ is defined as:
- $\ds A_n := \dfrac 1 n \sum_{k \mathop = 1}^n x_k$
That is, to find out the arithmetic mean of a set of numbers, add them all up and divide by how many there are.
Also known as
This is the quantity that is usually referred to in natural language as the "average" of a set of numbers.
It is also known as the common mean, or just mean value or mean.
Also see
Note that there are several kinds of average and indeed, several different kinds of mean. This is just one of them.
- Definition:Arithmetic-Geometric Mean
- Definition:Geometric Mean
- Definition:Harmonic Mean
- Definition:Hölder Mean
- Definition:Weighted Mean
Other measures of central tendency that are often introduced in schools at the same time:
- Results about arithmetic mean can be found here.
Linguistic Note
In the context of an arithmetic mean, the word arithmetic is pronounced with the stress on the first and third syllables: a-rith-me-tic, rather than on the second syllable: a-rith-me-tic.
This is because the word is being used in its adjectival form.
Sources
- 1964: Milton Abramowitz and Irene A. Stegun: Handbook of Mathematical Functions ... (previous) ... (next): $3$: Elementary Analytic Methods: $3.1$ Binomial Theorem etc.: Arithmetic Mean of $n$ quantities $A$: $3.1.11$
- 1968: Murray R. Spiegel: Mathematical Handbook of Formulas and Tables ... (previous) ... (next): $\S 36$: Inequalities: Inequalities involving Arithmetic, Geometric and Harmonic Means: $36.5$
- 1977: K.G. Binmore: Mathematical Analysis: A Straightforward Approach ... (previous) ... (next): $\S 3$: Natural Numbers: $\S 3.10$: Example
- 1977: K.G. Binmore: Mathematical Analysis: A Straightforward Approach ... (previous) ... (next): $\S 1$: Real Numbers: Exercise $\S 1.12 \ (5)$
- 1977: K.G. Binmore: Mathematical Analysis: A Straightforward Approach ... (previous) ... (next): $\S 3$: Natural Numbers: $\S 3.10$: Example
- 1986: Geoffrey Grimmett and Dominic Welsh: Probability: An Introduction ... (previous) ... (next): $\S 2.3$: Functions of discrete random variables: $(18)$
- 1989: Ephraim J. Borowski and Jonathan M. Borwein: Dictionary of Mathematics ... (previous) ... (next): arithmetic mean or mean
- 1998: David Nelson: The Penguin Dictionary of Mathematics (2nd ed.) ... (previous) ... (next): arithmetic mean
- 1998: David Nelson: The Penguin Dictionary of Mathematics (2nd ed.) ... (previous) ... (next): mean: 1.
- 2008: David Nelson: The Penguin Dictionary of Mathematics (4th ed.) ... (previous) ... (next): arithmetic mean
- 2008: David Nelson: The Penguin Dictionary of Mathematics (4th ed.) ... (previous) ... (next): mean: 1.
- 2014: Christopher Clapham and James Nicholson: The Concise Oxford Dictionary of Mathematics (5th ed.) ... (previous) ... (next): arithmetic mean
- 2014: Christopher Clapham and James Nicholson: The Concise Oxford Dictionary of Mathematics (5th ed.) ... (previous) ... (next): mean
- 2021: Richard Earl and James Nicholson: The Concise Oxford Dictionary of Mathematics (6th ed.) ... (previous) ... (next): arithmetic mean
- 2021: Richard Earl and James Nicholson: The Concise Oxford Dictionary of Mathematics (6th ed.) ... (previous) ... (next): mean