A scatterplot in which every dot is a different county in California displays on its horizontal axis the percentage of the county 25 years and older that has at most a high school education and on its vertical axis the number of water vending machines per 10,000 people in the county. The plot shows a positive correlation between the two variables; counties that have a higher share of residents with at most a high school education generally having more water vending machines after adjusting for population. Each dot's size is scaled by the county population, such that larger counties appear as larger dots.