In response to complaints about high prices, a grocery chain runs the following advertising campaign: If you pay your child $6 to go buy $50 worth of groceries, then your child makes twice as much on the trip as we do. Youve collected the following information from the grocery chains financial statements:

(millions)

Sales $ 549

Net income 30

Total assets 482

Total debt 369

What is the profit margin for the store? (in %) (round to 4 decimal places)