Retail Inc. uses the FIFO cost formula in a perpetual inventory system. Below is the inventory record for September, 2021: Sep 1 Beginning inventory 20 units @ $19 per unit Purchases Sep 7 70 units @$20 per unit 8 Sales 50 units @$30 per unit Sales 25 units @$31 per unit 10 Purchases 50 units @$22 per unit Sep 22 Sales 40 units @ $28 per unit If Retail Inc. used the average cost formula instead of FIFO, gross profit from the September 8 sale would be cannot be determined. higher. lower. the same.