On May 1, 2021, Sentra had an inventory of 60 units at a cost of 24 per unit. Sentra uses a periodic method for inventory. During the month, purchases and sales were as follows: REQUIRED: a) Determine the cost of goods available for sale. b) Determine (1) the ending inventory and (2) the cost of goods sold under the two assumed cost flow methods (FIFO and average-cost). c) Which cost flow method results in (1) the lower ending inventory amount for the statement of financial position, and (2) the lower cost of goods sold for the income statement