Can you explain how to figure out sales?

Warnerwoods Company uses a perpetual inventory system. It entered into the following purchases and sales transactions for March.

Date	Activities	Units Acquired at Cost			Units Sold at Retail
March 1	Beginning inventory	60	units	@ $50.20 per unit
March 5	Purchase	205	units	@ $55.20 per unit
March 9	Sales				220	units	@ $85.20 per unit
March 18	Purchase	65	units	@ $60.20 per unit
March 25	Purchase	110	units	@ $62.20 per unit
March 29	Sales				90	units	@ $95.20 per unit
	Totals	440	units		310	units

4. Compute gross profit earned by the company for each of the four costing methods. For specific identification, units sold include 45 units from beginning inventory, 175 units from the March 5 purchase, 25 units from the March 18 purchase, and 65 units from the March 25 purchase. (Round weighted average cost per unit to two decimals and final answers to nearest whole dollar.)