Which type of chart shows the relationship for more than one variable?

• A. Bar graphs
• B. Histogram
• C. Gantt chart
• D. Pie chart

Answer: (A)

When you want to show how two variables relate across categories, you need a chart that can display multiple data series side by side within each category. Bar graphs fit this because they can be configured as grouped bars or stacked bars, allowing you to compare two or more series at each category and see how the variables relate. For example, you could compare two groups across several departments, or show counts for different categories within each group, and the pattern across categories reveals the relationship between the variables.

Histograms depict the distribution of a single continuous variable. Pie charts show portions of a whole for one variable and emphasize composition rather than relationships. Gantt charts illustrate tasks over time and are used for project scheduling, not for showing relationships between variables.

So bar graphs are the best choice for illustrating relationships involving more than one variable among these options.