What type of graph is used to show relationships between two quantitative variables?

A line graph is the appropriate choice for displaying relationships between two quantitative variables because it effectively shows how one variable changes in relation to another. In a line graph, data points representing values for each variable are plotted on a two-dimensional grid, with one axis typically representing the independent variable and the other the dependent variable. This allows for the visualization of trends, patterns, or correlations between the two variables over time or across measurements.

Additionally, line graphs are particularly useful when the data involves continuous variables, as the line connecting the points helps to illustrate changes and relationships more clearly than other types of graphs would. This makes them a preferred option in fields such as science and economics where analysis of trends is vital. Other types of graphs, such as bar graphs, pie charts, or histograms, have different uses and may not effectively convey the relationship between two quantitative variables as well as a line graph does.