The units of Manganese Plus available for sale during the year were as follows: Mar. 1 Inventory 16 units @ $30 $ 480 June 16 Purchase 30 units @ $35 1,050 Nov. 28 Purchase 45 units @ $39 1,755 91 units $3,285 There are 15 units of the product in the physical inventory at November 30. The periodic inventory system is used. 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. Round interim calculations and final answer to two d ecimal places. $