Segmented bar chart

Each bar stands for one category of the first variable, and the pieces inside that bar show how that group divides across the second variable, which is its conditional distribution. When every bar is drawn to a common height of 100 percent, you compare segment sizes across bars to judge association. For example, if 30 of 50 freshmen play a sport but only 16 of 40 seniors do, the freshman bar is $30 / 50 = 0.60$ sport and the senior bar is $16 / 40 = 0.40$, so the two groups differ. If all the bars split in the same proportions, the two variables show no association in the sample.