What chart type should be used to illustrate sales across multiple states if the goal is to show relative sizes?

A pie chart is an effective choice for illustrating sales across multiple states when the goal is to show relative sizes. This chart type presents data in a circular graph divided into slices, where each slice represents a portion of the whole. In the context of sales across different states, the size of each slice corresponds to the sales volume for each state, visually conveying the proportion of sales relative to the total across all states.

The pie chart allows for a straightforward comparison between the different states, making it immediately clear which states have larger or smaller sales figures. Viewers can quickly grasp how each state's sales contribute to the total sales, facilitating a visual assessment of relative sizes.

While other chart types, such as donut charts, might offer a similar visual representation by also emphasizing parts of a whole, they do not enhance the understanding of the data beyond what a pie chart provides. Area charts and clustered column charts typically serve different analytical purposes, illustrating trends over time or comparing discrete categories but not necessarily emphasizing the relative size component as effectively as pie charts do in this particular case.