4.1: Mean - Weighted Arithmetic Mean

There are sets of values where the values or measurements involved have different “weights” or degree of importance. The mean of this set is called a “weighted mean.” The formula for computing a weighted mean is as follows:

where:
= mean
x = measurement or value
W = weight

Example:
Ina’s subjects and the corresponding number of units and grades.

To compute for the weighted mean, multiply each value (in this case the grade) with the corresponding weight (in the example, the number of units). Get the sum of all the products then divide it by the total number of weights (sum of all units).

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