What visual representation shows the relationship between two variables using a cluster of dots?

A scatterplot is a type of visual representation used to display the relationship between two quantitative variables. It consists of a set of points, where each point represents an observation in the dataset, with one variable plotted along the x-axis and the other along the y-axis. This clustering of dots allows for easy visualization of patterns, trends, or correlations between the two variables.

For example, if you're examining the relationship between study hours and test scores, each student's study hours would be on one axis, and their test scores on the other. The resulting scatterplot would help identify whether higher study hours correlate with higher test scores, or if there is no apparent relationship.

The other types of visual representations mentioned serve different purposes. A histogram is used for displaying the distribution of a single quantitative variable, while a bar chart is suited for comparing categorical data or showing quantities associated with different categories. A line graph typically represents data trends over time and connects points with lines rather than displaying independent observations.