EXAMPLE 2.26 Wine Purchased When No Music Was Playing
CASE 2.2 What types of wine were purchased when no music was playing? To answer this question, we find the marginal distribution of wine type for the value of music equal to none. The counts we need are in the first column of our table:
| Music | |
|---|---|
| Wine | None |
| French | 30 |
| Italian | 11 |
| Other | 43 |
| Total | 84 |
What percent of French wine was sold when no music was playing? To answer this question, we divide the number of bottles of French wine sold when no music was playing by the total number of bottles of wine sold when no music was playing:
108
In the same way, we calculate the percents for Italian and other types of wine. Here are the results:
| Wine type: | French | Italian | Other |
| Percent when no music is playing: | 35.7 | 13.1 | 51.2 |
Other wine was the most popular choice when no music was playing, but French wine has a reasonably large share. Notice that these percents sum to 100%. There is no roundoff error here. The distribution is displayed in Figure 2.22.
