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)'.
To average these values, do a weighted average using the number of occurrences of each value as the weight. To calculate a weighted average: 1. Multiply each value by its weight. (Ans: 20, 16, 5, 40, 24, 14, 68, and 0).2. Add up the products of value times weight to get the total value. (Ans: Sum=187). 3.o calculate a weighted average: 1. Multiply each value by its weight. (Ans: 20, 16, 5, 40, 24, 14, 68, and 0). 2. Add up the products of value times weight to get the total value. (Ans: Sum=187). 3.