Marigold Inc. uses the perpetual inventory system and the weighted average cost formulato value inventories. On August 1, there were 5000 units valued at $9000 in the beginning units were purchased for So per unit. On August 15.7000 units were sold for $10 per unit. The amount charged to cost of goods on August 15 was to On A 0000 $21000 $31500 $42000 $28700