Which chart type is best for comparing values across categories?

A bar chart is the most effective choice for comparing values across different categories. This type of chart displays individual bars for each category, allowing viewers to easily compare their lengths and thus the values they represent. Each bar's height or length corresponds to a numerical value, making it straightforward to see which categories have higher or lower values at a glance.

In comparison:

• A line graph is typically used to show trends over time, making it less suitable for directly comparing distinct categories.

• A pie chart illustrates proportions of a whole, which can obscure direct comparisons because the viewer must assess angles and areas rather than straightforward lengths.

• A scatter plot is designed to show the relationship between two variables and is not intended for comparing category values directly.

The simplicity and clarity of a bar chart in showcasing categorical comparisons is why it is the preferred choice in this scenario.