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 Aug. 7 Dec. 11 Available for sale Inventory Purchase Purchase 15 units at $4,000 $ 60,000 21 units at $4,600 96,600 18 units at $5,100 91,800 54 units $248,400 There are 17 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