Question

The scatterplot and regression line below show the relationship between the percentage of American adults who smoke and years since 1945. The fitted line has a

y-intercept of 41. What is the best interpretation of this
y-intercept?
a. In 1945, 41% of American adults smoked.
b. In 1945, the percentage of American adults who smoked began at 41% and increased.
c. In 1945, the percentage of American adults who smoked began at 41% and decreased.
d. In 1945, 41% of American adults did not smoke.

Answer 1

The y-intercept of 41 in the regression line implies that in 1945, 41% of American adults smoked.

Step-by-step explanation:

The best interpretation of the y-intercept of 41 in the regression line that shows the relationship between the percentage of American adults who smoke and years since 1945 is: In 1945, 41% of American adults smoked. The y-intercept represents the expected value of the dependent variable (in this case, the percentage of American adults who smoked) when the independent variable (years since 1945) is zero. Therefore, at the starting point of this data set, or in the year 1945, the model predicts that 41% of American adults were smokers.