A record of transactions for the month of May was as follows: Purchases Sales May 1 (balance) 400 a $4.20 May 3 4 1.300 @ $4.10 6 8 800 a $4.30 12 14 700 @ $4.40 200 @ $7.00 1,000 @ 7.00 900 a 7.50 (a) Assuming that perpetual inventory records are kept in dollars, determine the inventory using the average cost method. (b) Calculate the gross profit