Chapter 1.3, Problem 11E

Cigarette smoking. The data in Table 7 shows that the percentage of female cigarette smokers in the United States declined from $22.1\%$ in 1997 to $13.6\%$ in 2015.

Applying linear regression to the data for females in Table 7 produces the model $f=-0.45t+22.20$

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.

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