Mary Company uses the periodic inventory system. The following May data are for an item in Mary's inventory: May 1 Beginning inventory, 150 units @ $30 per unit. 12 Purchased 100 units @ $35 per unit. 16 Sold 180 units. 24 Purchased 170 units @ $40 per unit. Calculate the cost of goods sold for May and ending inventory at May 31 using (a) first-in, first-out, (b) last-in, first-out, and (c) the weighted-average cost method. Round the cost per unit to three decimal places and your final answers to the nearest dollar.