Award: $10\mathrm{.}00$ points Problem $3-21$ Profit Margin $[$LO$4]$ In response to complaints about high prices, a grocery chain runs the following advertising campaign: $"$If you pay your child $8$ 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$,600\mathrm{.}0$