Weighted average

From Glossary of Meteorology

weighted average

A representative value for a set of numbers x1, x2, · · ·, xn given by the sum w1x1 + w2x2 + · · · + wnxn, where the numbers wi are the weights.

The weights are usually assigned positive values that sum to unity. If all the weights are equal, the weighted mean reduces to the arithmetic mean.