The units of Manganese Plus available for sale during the year were as follows: 22 units $31 $682 Mar. 1 Inventory 30 units Purchase @ $33 June 16 990 Purchase $36 Nov. 28 45 units 1,620 97 units $3,292 There are 14 units of the product in the physical inventory at November 30. The periodic inventory system is used. Round answers to the nearest whole dollar. a. Determine the inventory cost by the FIFO method. b. Determine the inventory cost by the LIFO method. c. Determine the inventory cost by the average cost methods