E4A on page 315 (part one) and E6A on page 316 by calculating part one using only the average cost method.

Periodic inventory system and inventory costing methods E4A. In chronological order, the inventory, purchases, and sales of a single product for a recent month are as follows. Units Amount per Unit June 1 Beginning inventory 150 $30 4 Purchase 400 12 Purchase 800 36 16 Sale 1,300 60 24 Purchase 300 39 1. Using the periodic inventory system, compute the cost of ending inventory, cost of goods sold, and gross margin. Use the average-cost, FIFO, and LIFO inventory costing methods. (Round unit costs to cents and totals to dollars.)