# SigmaXY Command

From GeoGebra Manual

- SigmaXY[List of x-Coordinates, List of y-Coordinates]
- Calculates the sum of the products of the
*x*- and*y*-coordinates. - SigmaXY[List of Points]
- Calculates the sum of the products of the
*x*- and*y*-coordinates. - Example: You can work out the covariance of a list of points using
`SigmaXY[list]/Length[list] - MeanX[list] * MeanY[list]`.