Wine and heart disease. Drinking moderate amounts of wine may help prevent heart attacks. Let’s look at data for entire nations. Table 15.1 gives data on yearly wine consumption (liters of alcohol from drinking wine, per person) and yearly deaths from heart disease (deaths per 100,000 people)

in 19 developed countries in 2001.

TABLE 15.1 Wine consumption and heart disease Alcohol Heart disease Alcohol Heart disease Country from winea death rateb Country from winea death rateb Australia 3.25 80 Italy 7.50 60 Austria 4.75 100 Netherlands 2.75 70 Belgium 2.75 60 New Zealand 2.50 100 Canada 1.50 80 Norway 1.75 80 Denmark 4.50 90 Spain 5.00 50 Finland 3.00 120 Sweden 2.50 90 France 8.50 40 Switzerland 6.00 70 Germany 3.75 90 United Kingdom 2.75 120 Iceland 1.25 110 United States 1.25 120 Ireland 2.00 130 aLiters of alcohol from drinking wine, per person.

bDeaths per 100,000 people, ischemic heart disease.

Chapter 15 Exercises 329

(a) Make a scatterplot that shows how national wine consumption helps explain heart disease death rates.

(b) Describe in words the direction, form, and strength of the relationship.

(c) The correlation for these variables is r = −0.645. Why does this value agree with your description in part (b)?