Wojcik Company uses the perpetual inventory system. The following information is available for the month of May: Date Units Purchases Cost Sales Units Price Beginning 30 $ 8 inventory May 10 10 $12 May 15 10 $20 May 18 15 $14 May 21 15 $20 May 30 10 $15 I Instructions a. Calculate the cost of goods sold and ending inventory using the FIFO method of inventory valuation. b. Calculate the cost of goods sold and ending inventory using the LIFO method of inventory valuation. c. Calculate the cost of goods sold and ending inventory using the Average Cost method of inventory valuation. d. Record the journal entries for the May 10, 18 and 30 purchases and the May 15 and 21 sales using the Average Cost method