(Appendix 6B) Inventory Costing Methods: Periodic Average Cost Filimonov inc. has the following information related to purchases and sales of one of its inventory items: Assume that Filimonov uses a periodic inventory system. Required: Calculate the cost of goods sold and the cost of ending inventory using the averoge cost method. (Note: Use four decimal places for per-unit calculations and round all other numbers to the nearest dollar.)