Answer : 25 miles per gallon
According to the graph, the distance traveled by a car is plotted against the gallon of gasoline consumed
Distance = y
Gallon of gasoline = x
We want to calculate the distance the car traveled per gallon of gasoline consumed
Firstly, Pick a point of the graph
From the graph, we picked 4 points which are
x1 = 4, x2 = 8, y1 = 100 and y2 = 400
Point A = (4, 100) and point B = (8, 200)
[tex]\begin{gathered} \text{Slope = }\frac{dis\tan ce\text{ covered by car}}{\text{gallon of gasoline}} \\ \text{Slope = }\frac{y2\text{ - y1}}{x2\text{ - x1}} \\ \text{Slope = }\frac{200\text{ - 100}}{8\text{ - 4}} \\ \text{Slope = }\frac{100}{4} \\ \text{Slope = 25 miles / gallon} \\ \text{For every 25 miles traveled by the car, 1 gallon of gasoline is consumed} \end{gathered}[/tex]