eriodic Inventory by Three Methods he units of an item available for sale during the year were as follows: Jan. 1 Inventory 10 units @ $27 Feb. 17 Purchase 18 units @ $29 July 21 Purchase 15 units @ $30 Nov. 23 Purchase 20 units @ $31 There are 10 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 tc dollar, if required. Prev All work saved. 5