1 EX 7-13 Periodic inventory by three methods; cost of merchandise sold OBJ. 2,4 The units of an item available for sale during the year were as follows: Jan. Inventory 900 units at $54 Mar. 10 Purchase 1,120 units at $55 Aug. 30 Purchase 1,000 units at $58 Dec. 12 Purchase 980 units at $60 There are 1,000 units of the item in the physical inventory at December 31. The periodic inventory system is used. Determine the inventory cost and the cost of merchandise sold by three methods, presenting your answers in the following form: Cost Merchandise Inventory Merchandise Sold Inventory Method a. First-in, first-out b. Last-in, first-out c. Weighted average cost