Question

"Make Mine a Large" In the 2009 New York Times piece "Excess Pounds, but Not Too Many, May Lead to Longer Life," author Roni Caryn Rabin reported: Being overweight won't kill you—it may even help you live longer. That's the latest from a study that analyzed data on 11,326 Canadian adults, ages 25 and older, who were followed over a 12-year period. The report ... found that overall, people who were overweight but not obese—defined as a body mass index of 25 to 29.9—were actually less likely to die than people of normal weight, defined as a B.M.I. of 18.5 to 24.9. By contrast, people who were underweight, with a B.M.I. under 18.5, were more likely to die than those of average weight. Their risk of dying was 73% higher than that of normal weight people. Question 1. Although this article doesn't describe an experiment, it does imply that being a little overweight may lead to a longer life. Identify at least one confounding variable that may compromise the validity of this inference. Support your case.

          "Make Mine a Large"
In the 2009 New York Times piece "Excess Pounds, but Not Too Many, May Lead to Longer Life," author Roni Caryn Rabin reported:
Being overweight won't kill you—it may even help you live longer. That's the latest from a study that analyzed data on 11,326 Canadian adults, ages 25 and older, who were followed over a 12-year period. The report ... found that overall, people who were overweight but not obese—defined as a body mass index of 25 to 29.9—were actually less likely to die than people of normal weight, defined as a B.M.I. of 18.5 to 24.9.
By contrast, people who were underweight, with a B.M.I. under 18.5, were more likely to die than those of average weight. Their risk of dying was 73% higher than that of normal weight people.
Question
1. Although this article doesn't describe an experiment, it does imply that being a little overweight may lead to a longer life. Identify at least one confounding variable that may compromise the validity of this inference. Support your case.

"Make Mine a Large"
In the 2009 New York Times piece "Excess Pounds, but Not Too Many, May Lead to Longer Life," author Roni Caryn Rabin reported:
Being overweight won't kill you—it may even help you live longer. That's the latest from a study that analyzed data on 11,326 Canadian adults, ages 25 and older, who were followed over a 12-year period. The report ... found that overall, people who were overweight but not obese—defined as a body mass index of 25 to 29.9—were actually less likely to die than people of normal weight, defined as a B.M.I. of 18.5 to 24.9.
By contrast, people who were underweight, with a B.M.I. under 18.5, were more likely to die than those of average weight. Their risk of dying was 73% higher than that of normal weight people.
Question
1. Although this article doesn't describe an experiment, it does imply that being a little overweight may lead to a longer life. Identify at least one confounding variable that may compromise the validity of this inference. Support your case.

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