5. Sarah's Sweaters uses the periodic inventory system: Inventory Purchases: Date # of Units Cost per Unit Total Cost 1-1 10,000 $10 $100,000 3-1 20,000 $12 $240,000 6-1 30,000 $15 $450,000 9-1 40,000 $18 $720,000 Total 100,000 $1,510,000 In 2020, 80,000 units were sold and 20,000 remain in ending inventory Required: Calculate cost of goods sold and ending inventory using First In First Out, Last in First Out, and Weighted Average