Mar. 1 Beginning inventory 160 units @ $52.20/unit
Mar. 5 Purchase 255 units @ $57.20/unit
Mar. 9 Sales 320 units @ $87.20/unit
Mar. 18 Purchase 115 units @ $62.20/unit
Mar. 25 Purchase 210 units @ $64.20/unit
Mar. 29 Sales 190 units @ $97.20/unit

Totals 740 units 510 units

To calculate cost of inventory sold using the FIFO method:

Your sales on Mar 9 will include 160 units at the Mar 1 beginning inventory price and 160 units at the Mar 5 purchase price.

Your sales on Mar 29 will include 95 units at the Mar 5 purchase price and the remaining units sold will be at the Mar 18 purchase price