The following information is taken from the inventory records of the CNB Company for the month of September: Beginning inventory, 9/1/2018 Purchases: 7, 000 uni ts $11.00 5,000 units $11.00 8, 000 units $11. 50 9/25 Sales: 9/10 9/29 7, 500 units 9, 000 units 3, 500 units were on hand at the end of September. Required . Assuming that CNB uses a periodic inventory system and employs the average cost method, determine cost of goods sold for September and September's ending inventory. 2. Repeat requirement 1 assuming that the company uses a perpetual inventory system