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.
-How would you interpret the slope of the regression line in the context of the problem? Select all that apply.
A) Every 8,000 powerboat registrations is associated with a predicted increase of one manatee death.
B) We predict an additional 0.12 manatee death for each single powerboat registration.
C) We predict an additional 0.12 manatee death for every 1,000 powerboats registered.
D) We predict a decrease of 41.43 manatee deaths for every 1,000 powerboats registered.

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. 
-How would you interpret the slope of the regression line in the context of the problem? Select all that apply.
A) Every 8,000 powerboat registrations is associated with a predicted increase of one manatee death. 
B) We predict an additional 0.12 manatee death for each single powerboat registration. 
C) We predict an additional 0.12 manatee death for every 1,000 powerboats registered. 
D) We predict a decrease of 41.43 manatee deaths for every 1,000 powerboats registered.

Quizplus · Accepted Answer

The slope of the regression line indicates the change in the dependent variable (manatee deaths) for a one-unit change in the independent variable (powerboat registrations). A and C correctly interpret the slope in terms of the given units.

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