COVAR function
Description
Covariance function.
COVAR(range1,range2) returns the covariance of the data in range1 and range2.
$$ covar(x,y) = \frac {1}{n} \sum_{}^{}{ (x-\bar{x})(y-\bar{y}) } $$
The arguments range1 and range2 can be a list of numbers, cell addresses, cell ranges (such as A1:A10).
Range1 and range2 can also be vectors (column or row matrices) with the same number of elements.