The title of this exercise was a recent headline. The article goes on to describe a study in which men’s walking speeds at age 70 were measured and then the men were followed over several years. In the study, men who walked slowly were more likely to die. The article concludes that ‘‘Men can elude the Grim Reaper by walking at speeds of at least 3 miles per hour.” What common mistake is this article making? What is a possible confounding variable?