Annual measurements of the number of powerboat registrations (in thousands) and the number of manatees killed by powerboats in Florida were collected over the 14 years 1977-1990. A scatterplot of the data, least squares regression line, and correlation coefficient follow.
-The y-intercept is not a valid prediction of manatee deaths. Why?
A) It is an example of extrapolation.
B) We cannot observe a negative number of manatee deaths.
C) Both A and B
D) Neither A nor B

Question

Annual measurements of the number of powerboat registrations (in thousands) and the number of manatees killed by powerboats in Florida were collected over the 14 years 1977-1990. A scatterplot of the data, least squares regression line, and correlation coefficient follow. 
-The y-intercept is not a valid prediction of manatee deaths. Why?
A) It is an example of extrapolation. 
B) We cannot observe a negative number of manatee deaths. 
C) Both A and B 
D) Neither A nor B

Quizplus · Accepted Answer

The y-intercept might predict a negative number of manatee deaths, which is not possible, and using it for prediction can be considered extrapolation if it falls outside the range of observed data.

Annual Measurements of the Number of Powerboat Registrations (In Thousands)