The units of Manganese Plus available for sale during the year were as follows: Mar. 1 Inventory 23 units @ $29 $667 June 16 Purchase 31 units $32 992 Nov. 28 Purchase 39 units @ $37 1,443 93 units $3,102 There are 16 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