uie 1orm illustrated in Exhibit 5. EX 6-12 Periodic inventory by three methods The units of an item available for sale during the year were as follows: OBJ.2, 4 Jan. 1 Feb. 17 Inventory 200 units at $60 Purchase275 units at $64 Purchase300 units at $68 Purchase 225 units at $70 July 21 Nov. 23 There are 220 units of the item in the physical inventory at December 31. The periodic tory system is used. Determine the inventory cost by (a) the first-in, first-out method, (b) the last-in, first-out method, and (c) the weighted average cost method