The inventory records for Radford Co. reflected the following

Beginning inventory @ May 1 1,700 units @ $ 5.00

First purchase @ May 7 1,800 units @ $ 5.20

second purchase @ May 17 2,000 units @ $ 5.30

Third purchase @ May 23 1,600 units @ $ 5.40

Sales @ May 31 5,400 units @ $ 6.90

Determine the amount of gross margin assuming the FIFO cost flow method.