Final answer:
A scatter plot and a line graph are most effective for representing the relationship between two continuous variables, which allow for visualization of how one variable changes in relation to another over a continuous range.
Step-by-step explanation:
A scatter plot and line graph are best used when comparing an independent and a dependent variable that are both Continuous. Scatter plots and line graphs are graphical representations that show the relationship between two continuous variables, which are typically quantifiable and measurable. These types of graphs are ideal for displaying how one variable changes in response to another over a continuous range. For example, line graphs are often used in physics to demonstrate how one quantity changes in response to the other, such as the distance a train travels from its station over time.
In contrast, categorical variables represent groups or categories, and bar graphs are more suitable for such data. Nominal and discrete variables are also not represented best by scatter plots and line graphs; histograms or bar charts might be more appropriate in those cases. Therefore, for continuous variables, scatter plots and line graphs provide a clear visual representation of the trends and relationships between the variables.