Chapter 1.3, Problem 11E

Cigarette smoking. The data in Table 7 shows that the percentage of female cigarette smokers in the U.S. declined from 22.1% in 1997 to 17.3% in 2010.

(A) Applying linear regression to the data for females in Table 7 produces the model

$f=-0.39t+21.93$

where $f$ is percentage of female smokers and $t$ is time in years since 1997. Draw a scatter plot of the female smoker data and a graph of the regression model on the same axes for $0\le t\le 15$.

(B) Estimate the first year in which the percentage of female smokers is less than 10%.