Some purchasing specialist jobs also assign specialists to track the maintenance of office equipment. Maintaining records of warranties and service agreements is sometimes expected of a person in this position.
A retail price index would take this into account and use a weighted average which gives more prominence to commonly bought items. Excel does not contain a built in function to calculate a weighted average. It is however easy to do it using the SUMPRODUCT() function in a simple formula. SumProduct() multiplies two arrays (or ranges) together and returns the sum of the product. In the illustration it would calculate '(B4 x C4) + (B5 x C5) + (B6 x C6)'.
Weighted Averages In Excel. This page describes how to calculate a weighted average. Introduction. In a normal average, each value to be included in the average with equal significance. For example, the uweighed average of 65, 60, 80, and 95 is (65+60+80+95)/4 or 75.or example, if we use as weights percentages, the weights in the example above become 14%, 14%, 29%, and 43%. (These values are calculated by dividing each weight by the sum of the weights.) Since these percentages sum to 100% or 1.0, we can omit the SUM function and simplify the formula to.