Periodic Inventory by Three Methods The units of an item available for sale during the year were as follows: Jan. 1 Inventory 14 units @ $31 Feb. 17 Purchase 9 units @ $32 13 units @ $35 Jul. 21 Purchase Nov. 23 Purchase 20 units @ $37 There are 22 units of the item 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 dollary 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