The inventory records for Radford Co. reflected the following: Beginning inventory First purchase @May 7 May 1 Second purchase @ May 17 Third purchase @May 23 Sales May 31 1,000 units @ $3.60 1,100 units @ $3.80 1,300 units @ $3.90 900 units @ $4.00 3,300 units @ $5.50 What is the amount of gross margin assuming the weighted-average inventory cost flow method? (Round your intermediate calcul to two decimal places.)