Periodic Inventory by Three Methods The units of an Item available for sale during the year were as follows: Jan. 1 Inventory 4 units $25 Feb. 17 Purchase 18 units @ $27 July 21 Purchase 5 units @ $30 Nov. 23 Purchase 18 units @ $32 There are 4 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. 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