Periodic Inventory by Three Methods; Cost of Merchandise Sold The units of an item available for sale during the year were as follows: an. Inventory Mar. 10 Purchase Aug. 30 Purchase Dec. 12 Purchase There are 80 units of the item in the physical inventory at December 31The periodic inventory system is used. Determine the inventory cost and the cost of merchandise sold by three methods. Round interim calculations to one decimal and final answers to the nearest whole dollar. 40 units@ $116 60 units@$128 30 units $136 70 units@$138 Cost of Merchandise Inventory and Cost of Merchandise Sold Inventory Method Herchandise Inventory Merchandise Sold Weighted average cost