1 Many early studies on the relationship between smoking and

1. Many early studies on the relationship between smoking and lung cancer in the 1950s found that smokers were about 13 times more likely to die from lung cancer than non-smokers. Still, people argued against a cause and effect conclusion, citing numerous possible confounding variables. Suppose a student argues that these studies are not convincing evidence because the researchers did not record the diet of the individuals. What more does the student need to say to provide a complete explanation of why diet is a potentially confounding variable? 2. A Research Center conducted a survey in February of 2006 in which American adults were asked, \"Generally, how would you say things are these days in your life- would you say that you are very happy, pretty happy, or not too happy?\" Of the 3012 respondents, 34% answered \"very happy,\" 50% said \"pretty happy,\" 15% responded \"not too happy\" and 1 % replied that they did not know. Construct a well labeled bar graph to display the results. 95

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