According to the description, you should add the weight of the additional fuel to 2207.8 pounds. This additional weight is the difference of volumes in gallons multiplied by the slope coefficient. So, you write and calculate W(82 gallons) = W(54 gallons) + 5.7*(82-54) = 2207.8 + 5.7*(82-54) = 2367.4 pounds. ANSWER