Chapter 9, Problem 28E

While the number of smokers for the general adult population is decreasing, it is not decreasing equally across all subpopulations (and for some groups it is actually increasing). For the 18-to-24 age group, the number of smokers was 8 million in 1965 and 6.3 million in 2009. (Source: “Trends in Tobacco Use,” American Lung Association, 2011.) Assuming the number of smokers in the 18-to-24 age group continues decreasing according to a negative linear growth model,

a. predict the number of smokers in the 18-to-24 age group in 2015 (round your answer to the nearest thousand).

b. predict in what year the number of smokers in the 18-to-24 age group will reach 5 million.