HShow Me How 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 18 units at $35 10 units at $36 9 units at $39 13 units at $4 There are 15 units of the nem in the physical Inventory at December 31. The periodic inventory system is used. Round average unit cost to one decimal and final answers to the nearest whole oolar, required a. Determine the inventory cost by the first-in, first-out method b. Determine the inventory cost by the last-n, first-out method . Determine the inventory cost by the weighted average cost method