XYZ Company employs a FIFO periodic inventory system and had the following inventory information available for the month of July: July 1 Beginning inventory 200 units @ $5.00 cost per unit July 3 Purchased 300 units @ $5.30 cost per unit July 8 Sold 180 units July 13 Purchased 100 units @ $5.80 cost per unit July 18 Sold 120 units July 20 Purchased 400 units @ $6.50 cost per unit July 28 Sold 250 units July 31 Purchased ??? units @ $5.20 cost per unit During July, XYZ Company reported an inventory turnover ratio of 1.20.Calculate the number of units XYZ Company purchased on July 31.