The units of Manganese Plus available for sale during the year were as follows: Mar. 1 Inventory June 16 Purchase 21 units 29 units @ $31 $651 @$30 870 Nov. 28 Purchase 45 units @ $39 1,755 95 units $3,276 There are 17 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.