# The Arithmetic Mean

A measure of average / location / central tendency. For a sample $\mathbf{x} = (x_1, x_2, \ldots, x_n)$, it is defined as follows:

$$\overline{\mathbf{x}} = (x_1 + x_2 + \ldots + x_n)/n$$## Examples

The mean of (1, 2, 3, 4, 5, 6, 273) is 42. ^{}

The mean number of animal legs is 3.96. ^{}

The mean country population is 34.2 million. ^{}

The mean number of Facebook friends is 338. ^{}

The mean Earth’s surface temperature is 15°C/59°F. ^{}

The mean number of dogs per US household is 1.46. ^{}

The mean number of moons of the Solar system planets is 36. ^{}