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 Inventory 200 units at $60 Feb. 17 July 21 Nov. 23 Purchase275 units at $64 Purchase 300 units at $68 Purchase 225 units at $70 There are 220 units of the item in the physical inventory at December 31. The periodic m 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