Which type of variable is primarily shown in a line chart?

A line chart is best suited for displaying continuous variables because it emphasizes the relationship between values over a continuous interval. Continuous variables can take on an infinite number of values within a given range, making them ideal for representation on a line chart, which connects data points with lines to illustrate trends and patterns clearly over time or another continuous scale.

For example, when visualizing data such as temperature changes over days, or stock prices over months, a line chart effectively conveys how these values evolve, showcasing trends that are critical in analysis. This visualization helps in understanding not just individual data points but also the overall trajectory of the data over time.

In contrast, categorical variables, discrete variables, and nominal variables don't have the same continuous nature and are usually represented in different chart formats. Categorical variables can involve grouping data into distinct categories, while discrete variables pertain to countable values. Nominal variables are a type of categorical variable without a specific order. These characteristics make them less suitable for a line chart, which relies heavily on the continuity of data points to demonstrate fluctuating values or patterns.