In response to complaints about high prices, a grocery chain runs the following advertising campaign: "If you pay your child $1 to go buy $32 worth of groceries, then your child makes about 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 Total assets Total debt $ 768.00 12.15 355.00 156.00 R a. What is the child's profit margin? Note: Do not round intermediate calculations and enter your answer as a percent rounded to 2 decimal places, e.g., 32.16.