In response to complaints about high prices, a grocery chain runs the following advertising campaign: If you pay your child $4 to go buy $100 worth of groceries, then your child makes twice as much on the trip as we do." You've collected the following information from the grocery chain's financial statements: ($ in millions) Sales Net income $640.0 12.8 Total assets 370.0 Total debt 240.0 a. b. What is the profit margin for the child as a percentage of what they spend and the profit margin for the store? (Do not round intermediate calculations. Enter your answers as a percent rounded to 2 decimal places, e.g., 32.16.) What is the store's ROE? (Do not round intermediate calculations. Enter your answer as a percent rounded to 2 decimal places, e.g., 32.16.) a. Child's profit margin % Store's profit margin % b. Store's ROE %