Which statement about bar charts is true?

• A. Bar charts may include color coding to represent levels of a second categorical variable
• B. Bar charts show distributions of a continuous variable
• C. Bar charts show relationships between two continuous variables
• D. Bar charts always show medians instead of means

Answer: (A)

Bar charts are built to compare categories and show a summary statistic for each category, such as counts, proportions, or means. They can also incorporate color or shading to encode a second categorical variable, for example using different colors to distinguish subgroups within each main category. This use of color within the bars or in stacked/grouped bars lets you see how a second factor varies across the primary categories.

Bar charts aren’t meant to display the distribution of a continuous variable—that’s what histograms or density plots are for. They also aren’t used to show the relationship between two continuous variables; a scatterplot is the appropriate choice there. And bar charts don’t inherently show medians; they typically display counts, proportions, or means, depending on the data and how the chart is constructed.