The estimated age-adjusted percent of persons 18 years of age and over who smoke cigarettes are shown below for females and males for selected years.
Estimated Age-Adjusted Percent Smoking Cigarettes
Year Female Male
1965 33.7 51.2
1974 16.9 42.8
1979 25.3 37
1985 22.5 32.2
1990 23.7 28
1995 15.4 26.5
1998 25.8 25.9
1999 22.9 25.2
2000 21.6 25.2
2001 30.1 24.6
2002 20.1 24.6
2003 19.4 23.7
a. Describe the linear relationship between the estimated age-adjusted percent smoking and time for females and males separately.
b. How much of the variation in the percents is accounted for by time for females and males? Interpret your findings.
c. Do females and males appear to have the same rate of decrease in the estimated age-adjusted percent smoking (explain answer)
d. Provide an estimate when the age-adjusted percent of males who smoke will equal the corresponding percent for females. What assumption(s) have you made in coming up with the estimate at this time point? (Hint: plot the regression lines)
e. Do you think this assumption is reasonable? Explain your answer.
This solution includes detailed answers that include regression outputs, charts, explanations, and interpretations of the findings.