Current Attempt in Progress Suppose that Amazon uses a periodic inventory system and reports the following for the month of June: (a) Compute the cost of the ending inventory and the cost of goods sold under (1) FIFO, (2) LIFO, and (3) average-cost. (Round average cost per unit to 2 decimal places, e.g. 5.25 and final answers to 0 decimal places, e.g. 2,520.)