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)'.
The weighted-average method (also called the average cost method) provides that the average unit cost is included in the cost of goods sold. Weighted-average (average cost) inventory costing method assumes that the average cost of inventories is to be recognized as the cost of goods sold.In order to determine the weighted-average, you need to add all costs of items on hand and divide the result by the number of items.In our example, the calculation is as follows: ($5,000 + $5,500) Ã· 2 = $5,250. This amount will be charged to the cost of goods sold when an item is sold.n order to determine the weighted-average, you need to add all costs of items on hand and divide the result by the number of items. In our example, the calculation is as follows: ($5,000 + $5,500) Ã· 2 = $5,250. This amount will be charged to the cost of goods sold when an item is sold.