Question

How are line graphs used to show how two variables are related?

Answer 1

A line graph is characterized by a correlation in the form of a line. The dependent variable is placed on the y-axis and the independent variable is on the x-axis. You can see their relation in terms of the slope. By definition, the slope is the ratio of the change of the y-coordinates to the change of the x-coordinates (Δy/Δx). Visually, you can determine the relationship of the variables by the orientation of the line as shown in the graph. If the slope is increasing, it means that the two variables are increasing together. If the slope is decreasing, it means that when x increases, y decreases. In other words, they are inversely proportional. You can also note the extent of change by knowing which has the greater slope.