Mantle Company's accounting records show the following at the year ending on December 31, 2021: Purchase Discounts $16,500 Freight-in 22,100 Purchases 413,000 Beginning Inventory 47,000 Ending Inventory 57,600 Purchase Returns 15,600 Using the periodic system, the cost of goods sold is O $423,600 O $392,400 $403,000 O $413,600