4. A company made the following merchandise purchases and sales during the month of July: Cost $15 each $20 each Transaction Purchase Purchase Sale Purchase Sale Purchase Units 380 270 500 300 250 350 Date July 1 July 9 July 14 July 20 July 30 $24 each $30 each There was no beginning inventory. Calculate the TOTAL cost of goods sold and ending inventory under (a) FIFO, (b) LIFO and the (3) average cost methods