The units of an item available for sale during the year were as follows: Jan. 1 Inventory 13 units at $48 Feb. 17 Purchase Jul. 21 Purchase 18 units at $49 12 units at $52 7 units at $53 Nov. 23 Purchase There are 10 units of the item in the physical inventory at December 31. The periodic inventory system is used. Ro and final answers to the nearest whole dollar, 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