Periodic Inventory by Three Methods The units of an item available for sale during the year were as follows: Jan. 1 Inventory 9 units $27 Feb. 17 Purchase 9 units $29 July 21 Purchase 7 units $32 Nov. 23 Purchase 14 units $33 There are 9 units of the item in the physical inventory at December 31. The periodic inventory system is used a. Determine the inventory cost by the first-in, first out method b. Determine the inventory cost by the last-in, first-out method. x c. Determine the inventory cost by the weighted average cost method. Round average unit cost to the nearest cent and final answers to the nearest whole dollar, if required.