On July 31, UFirst Inc. had the following merchandise transactions: July 1 7 19 25 Beginning inventory, 2 units @ $75 each Purchases, 4 units @ $80 each Sales, 5 units @ $180 each Purchases, 6 units @ $100 each (a) Calculate UFirst's cost of goods sold and ending inventory for the month of July assuming the use of (1) FIFO and (2) average cost in a perpetual inventory system. (b) Prepare comparative income statements for each cost method, assuming operating expenses of $300 and an income tax rate of 25%