COVAR(array1,array2)
COVAR returns the covariance of two data sets.
Let us assume that the cells A1, A2, ..., A5 contain numbers 11.4, 17.3, 21.3, 25.9, and 40.1, and the cells B1, B2, ... B5 23.2, 25.8, 29.9, 33.5, and 42.7. Then
COVAR(A1:A5,B1:B5) equals 65.858.