The y-axis of a graph represents the units for the dependent variable.

Yes, that's correct. On a standard Cartesian graph, the y-axis is the vertical axis and typically represents the dependent variable's values. This setup originates from a functional relationship where we define a function y = f(x), where y is the dependent variable, which depends on the value of the independent variable x. When you create a graph of such a function, the independent variable (x) is usually plotted along the horizontal axis (the x-axis), while the dependent variable (y) is plotted along the vertical axis (the y-axis).

In various types of data representations, such as scatter plots, line graphs, or bar graphs, the convention is the same: the outcome or the variable being studied to see how it reacts to changes (the dependent variable) is plotted on the y-axis. The variable that is manipulated or the one you have control over (the independent variable) is plotted on the x-axis.

For instance, in an experiment where you are studying how temperature (independent variable) affects the solubility of a substance (dependent variable), temperature would be plotted on the x-axis, and solubility on the y-axis. Here, solubility depends on temperature, so solubility is the dependent variable and would be represented on the y-axis.

Extra: Understanding the concepts behind the x and y axes on a graph is fundamental for data representation and analysis. In mathematics and many scientific fields, graphs are used to illustrate the relationship between two variables.

The independent variable is the one that you can vary or control in an experiment or study. It’s independent because its variation doesn't depend on other variables. On a graph, it is customarily plotted on the x-axis, which runs horizontally.

The dependent variable changes in response to the independent variable, and thus is called “dependent.” It is the focus of the research question, and you plot it on the y-axis, which runs vertically.

When you see a graph, by looking at the way the y-axis (dependent variable) changes in relation to the x-axis (independent variable), you can often infer the nature of the relationship between the two variables – for instance, whether the relationship is linear or nonlinear, direct or inverse, strong or weak – which helps in analyzing and understanding the scenario being studied.