The inventory records for Radford Company reflected the following: Beginning inventory @ May 1 First purchase @ May 7 Second purchase @ May 17 Third purchase @ May 23 Sales @ May 31 1,900 units @ $5.40 2,000 units @ $5.60 2,200 units @ $5.70 1,800 units @ $5.80 6,000 units @ $7.30 What is the amount of gross margin assuming the FIFO cost flow method