arrow onc. uses a perpetual inventory system. on january 22 2015 the company had 200 units of a particular product on hand with a total cost of$2400 the per unit costs were : on january 24,2015 arrow sold 65 units of this product using the three flow assumptions listed below,cmpute(1)the cost of goods sold and (2)the cost of the inventory of this product on hand after this sale.