A young child wonders what causes women to have babies. For each woman who lives on her block, she observes whether her hair is gray and whether she has young children. The four women with gray hair do not have young children, whereas all five women not having gray hair have young children. Noticing this association, the child concludes that not having gray hair is what causes women to have children.

(a) Form the contingency table displaying the data.

(b) Use this example to explain why association does not imply causation.