EXAMPLE 9.10
Health habits of college students: Conditional distributions. Let’s look at the data in the first column of the table in Example 9.9. There were 108 students with low physical activity. Of these, there were 69 with low fruit consumption. Therefore, the column proportion for this cell is
That is, 63.9% of the low physical activity students had low fruit consumption. Similarly, 25 of the low physical activity students has moderate fruit consumption. This percent is 23.1%.
538
In all, we calculate nine percents. Here are the results:
| Column percents for fruit consumption and physical activity | ||||
| Physical activity | ||||
| Fruit consumption | Low | Moderate | Vigorous | Total |
| Low | 63.9 | 46.5 | 46.4 | 48.1 |
| Medium | 23.1 | 28.4 | 26.9 | 27.1 |
| High | 13.0 | 25.1 | 26.7 | 24.8 |
| Total | 100.0 | 100.0 | 100.0 | 100.0 |
In addition to the conditional distributions of fruit consumption for each level of physical activity, the table also gives the marginal distribution of fruit consumption. These percents appear in the rightmost column, labeled “Total.”