please do the periodic weighted average method. thank you so much

Date Activities Units Acquired at Cost Units Sold at Retail Mar. 1 Beginning inventory 100 units @ $50.00 per unit Mar. 5 Purchase 400 units @ $55.00 per unit Mar. 9 Sales 420 units @ $85.00 per unit Mar. 18 Purchase 120 units @ $60.00 per unit Mar. 25 Purchase 200 units @ $62.00 per unit Mar. 29 Sales 160 units @ $95.00 per unit Totals 820 units 580 units Required