Zippy Shoe Co. uses a periodic inventory system. Zippy purchased 800 pairs of shoes at $70 each in June, 2,000 pairs in August at $72 each, and 1,200 pairs in December at $75 each. Zippy sold 3,800 pairs of shoes during the year. Required: Calculate the company's ending inventory and cost of goods sold using the each of following inventory costing methods. a. FIFO b. LIFO c. Weighted Average