The least squares regression equation ŷ = 0.7676x - 52.6841 relates the carbon dioxide emissions (in hundred thousands of tons), y, and energy produced (hundred thousands of megawatts), x, for all countries in the world.
(a) Interpret the slope.
(b) Is the y-intercept of the model reasonable? Why? What would you expect the y-intercept of the model to equal? Why?
(c) The lowest energy-producing country is Rwanda, which produces 0.094 hundred thousand megawatts of energy. The highest energy-producing country is the United States, which produces 4190 hundred thousand megawatts of energy. Would it be reasonable to use this model to predict the CO2 emissions of a country if it produces 6394 hundred thousand megawatts of energy? Why or why not?
(d) China produces 3260 hundred thousand megawatts of energy and emits 3120 hundred thousand tons of carbon dioxide. What is the residual for China? How would you interpret this residual?