The variables are Car Weight & Fuel Used. They are related by analyzing that the heavier the car is, the higher the use of fuel is.
Work Step by Step
On the graph, "Car Weight" is located under the x-axis, and to the left of the y-axis is "Fuel Used". The arrow placed on the graph goes diagonally up and to the right, implying that an increase in car weight yields an increase in fuel used.