Periodic Inventory by Three Methods The units of an item available for sale during the year were as follows: Jan. 1 Inventory Feb. 17 Purchase 4 units at $43 8 units at $45 Jul. 21 Purchase 9 units at $46 Nov. 23 Purchase 5 units at $48 There are 4 units of the item in the physical inventory at December 31. The periodic inventory system is used. Round a cent and final answers to the nearest whole dollar, if required. a. Determine the inventory cost by the first-in, first-out method. $ b. Determine the inventory cost by the last-in, first-out method. $ c. Determine the inventory cost by the weighted average cost method. $