The units of Manganese Plus available for sale during the year were as follows: 23 units @ $32 $736 Mar. 1 June 16 Inventory Purchase 29 units 986 $34 $38 Nov. 28 Purchase 42 units 1,596 $3,318 94 units There are 13 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