Suppose you are the principal at a troubled high school, and you want to find out why a lot of your students are dropping out of high school. You realize that two reasons your students are dropping out are: poor grades, and teen pregnancy. You also want to know whether being a boy or a girl affects why they are dropping out. So you find 200 students who have dropped out, 100 boys and 100 girls, and figure out why they dropped out.

The results turn out to be this: of the 100 boys who dropped out, all 100 of them dropped out due to poor grades. Of the 100 girls who dropped out, 75 of them dropped out due to teen pregnancy, and 25 due to poor grades.

Do you conclude that boys are 4 times as likely as girls to drop out due to poor grades?

Suppose you are the principle at a troubled high school, and you want to find out why a lot of your students are dropping out of high school. You realize that two reasons your students are dropping out are: poor grades, and teen pregnancy. You also want to know whether being a boy or a girl affects why they are dropping out. So you find 200 students who have dropped out, 100 boys and 100 girls, and figure out why they dropped out.

The results turn out to be this: of the 100 boys who dropped out, all 100 of them dropped out due to poor grades. Of the 100 girls who dropped out, 75 of them dropped out due to teen pregnancy, and 25 due to poor grades.

Do you conclude that boys are 4 times as likely as girls to drop out due to poor grades?