OBJ. 4 PE 7-5A Periodic inventory using FIFO, LIFO, and weighted average cost methods The units of an item available for sale during the year were as follows: Jan. 1 Inventory Aug. 7 Purchase Dec. 11 Purchase Available for sale 12 units at $5,400 $ 64,800 18 units at $6,000 108,000 15 units at $6,480 97,200 45 units $270,000 There are 14 units of the item in the physical inventory at December 31. The periodic inventory system is used. Determine the inventory cost using (a) the first-in, first-out (FIFO) method; (b) the last-in, first-out (LIFO) method; and (c) the weighted average cost method