5 3 In February, its first month of operations, a retailer made the following inventory purchases. Purchased 225 units at $7 each on Feb. 1. Purchased 400 units at $8 each on Feb. 10. Purchased 100 units at $9 each on Feb. 28. On Feb. 15, there were 300 units sold. The retailer used a perpetual inventory system. Using the FIFO cost formula, the cost of goods sold for the Feb. 15 sale was: $2,175. $2,800. $3,500. $1,525. 4