Answer Happy

4. A possible important environmental determinant of lung function in children is amount of cigarette smoking in the home. Suppose this question is studied by selecting two groups: Group 1 consists of 23 nonsmoking children 5-9 years of age with two parents who smoke, and have mean forced expiratory volume (FEV) of 2.1 L and a standard deviation of 0.7 L; group 2 consists of 20 non- smoking children of comparable age, with two parents who do not smoke, and have mean FEV of 2.3 L and a standard deviation of 0.4 L. (a) Do the children of two parents who smoke have mean FEV different from the children of two parents who do not smoke? Conduct a formal hypoth- esis test. Use a = 0.05. [10 marks (b) Summarize your findings in language that someone who has not taken a statistics course would understand. [5 marks) (c) Suppose you have been asked to assess the design of a new study address- ing the same question. In the new study, researchers plan to recruit 20 nonsmoking children 5-9 years of age with two parents who smoke and 20 nonsmoking children 5-9 years of age with two parents who do not smoke; children will be matched based on similar household income. Briefly ex- plain whether you believe the new study has more potential to show an association between smoke exposure and lung function than the original study. (5 marks)