Swifty Bookstore had 450 units on hand at January 1 , costing $9 each. Purchases and sales during the month of January were as follows: Swifty does not maintain perpetual inventory records. According to a physical count, 400 units were on hand at January 31. The cost of the inventory at January 31 , under the LIFO method is: $4540. $3600. $4800. $4400