# The Geometric Mean
The geometric mean of two numbers $a$ and $b$ (where $a \le b$) is a number $m$ such that
$
\frac m a = \frac b m
$
In other words, the geometric mean of two numbers is a number that is located exactly in-between the two numbers in a [[Geometric Sequence]].
The geometric mean can be used as a measure of central tendency of a population, in which case it is calculated by taking the n-th root of the product of all elements.
$
m = \left( \prod_{i=1}^n x_i \right)^\frac {1}{n}
$
The geometric mean is similar to [[The Arithmetic Mean]].