Marco Company uses a periodic inventory system. Determine the cost of ending inventory at July 31 and cost of goods sold (COGS) for July under weighted average. July 1: Beginning inventory: 50 units @ $4 total cost = $200 30 units @ $4.75 July 8: Purchase: total cost = $142.5 July 10: Sales: 55 units July 30: Purchase: 40 units@ $5 total cost = $200 The physical inventory count on July 31 shows 65 units on hand. O a Ending inventory of $248.70; COGS of $293.80 O b. Ending inventory of $293.80; COGS of $248.70 Oc. Ending inventory of $223.75; COGS of $318.75