(PECL stats >= 1.0.0)
stats_variance — Returns the variance
$a
[, bool $sample = FALSE
] ) : float
Returns the variance of the values in a.
aThe array of data to find the standard deviation for. Note that all values of the array will be cast to float.
sample
Indicates if a represents a sample of the
population; defaults to FALSE.
Returns the variance on success; FALSE on failure.