Inventory Costing Methods Spangler Company is a retailer that uses the periodic inventory system. On March 1, it had 100 units of product M at a total cost of $1,590. On March 6, Spangler purchased 200 units of M for $3,600. On March 10, it purchased 150 units of M for $3,000. On March 15, it sold 180 units of M for $5,400. Calculate the March cost of goods sold and the ending inventory at March 31 using (a) first-in, first-out, (b) last-in, first-out, and (c) the weighted-average cost method. Round your final answers to the nearest dollar