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)'.
Another type of average problem involves the weighted average-which is the average of two or more terms that do not all have the same number of members. To find the weighted term, multiply each term by its weighting factor, which is the number of times each term occurs.The formula for weighted average is:Example:nother type of average problem involves the weighted average-which is the average of two or more terms that do not all have the same number of members. To find the weighted term, multiply each term by its weighting factor, which is the number of times each term occurs.