I would use a proportion for the Fred's Fouls part. Use the closest point to 12 possible, which is (15, 69.5). Set up the proportion like so: 15/69.5 = 12/x Now cross multiply. 15x = 834 Now divide both sides by 15 to get x by itself. x = 55.6 Fred's Fouls will charge $55.60 for 12 wings. Now plug in 12 as x for the Carlie's Chicken part and solve for f(12). f(12) = 3.75(12) +10 f(12) = 45 +10 f(12) = 55 Carlie's Chicken will charge $55 for 12 wings.
