Which graph is best suited for visualizing the correlation between two variables on a Cartesian plane?

A scatter plot is ideal for visualizing the correlation between two variables on a Cartesian plane because it represents individual data points using two dimensions: one variable along the x-axis and the other along the y-axis. This allows for easy identification of relationships and trends between the two variables, such as whether an increase in one variable is associated with an increase or decrease in another, thereby depicting the strength and direction of their correlation.

In contrast, bar graphs are primarily used to compare categorical data rather than to illustrate relationships between two continuous variables. Histograms serve to show the distribution of a single variable by grouping data into bins, which won't depict any correlation with another variable. Similarly, box and whisker plots are effective for displaying the distribution of a single dataset, highlighting medians, quartiles, and potential outliers, but they do not show relationships between two variables. Therefore, the scatter plot stands out as the most suitable choice for examining how two variables interact with one another.