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 Jul. 21 Purchase Nov. 23 Purchase 1,050 units $140 1,440 units $142 1,570 units@ $145 1,150 units $146 There are 1,225 units of the item in the physical inventory at December 31. The periodic inventory system is used. Do not round interme 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