Use the methods from this chapter to explore and compare the cotinine measures in the three groups. Are there any notable differences? Are there any outliers? What do you conclude about the effects that smokers have on nonsmokers? Write a brief report of your conclusions, and provide supporting statistical evidence.

Data Set 12 “Passive and Active Smoke” in Appendix B lists measures of cotinine from three groups of subjects: (1) smokers; (2) nonsmokers exposed to environmental tobacco smoke; (3) nonsmokers not exposed to environmental tobacco smoke. Cotinine is an indicator of nicotine absorption.