GEOMEAN function
Description
Geometric mean function. GEOMEAN(range) computes the geometric mean of the contents of the cells in the specified range.
The argument range can be a list of numbers, cell addresses, cell ranges (such as A1:A10).
Range can also be a matrix. In that case the function returns a matrix with one row and the same number of columns, with each element the GEOMEAN of the corresponding column. If range is a row matrix, it is converted to a column matrix first.
The geometric mean is calculated as follows:
$$\left ( \prod_{i=1}^n{x_i} \right ) ^\tfrac1n = \sqrt[n]{x_1 x_2 \cdots x_n} = \exp\left[\frac1n\sum_{i=1}^n\ln x_i\right] $$
$$\left ( \prod_{i=1}^n{x_i} \right ) ^\tfrac1n = \sqrt[n]{x_1 x_2 \cdots x_n} = \exp\left[\frac1n\sum_{i=1}^n\ln x_i\right] $$ The geometric mean is undefined for a data set that contains zero or negative values.