The predicted amount of gas used when the outside temperatur

The predicted amount of gas used when the outside temperature is 17 degree-days

is about: ________ cubic feet. (Answer to the nearest cubic foot.)

Solution

The regression line of y from x is

y=81+19x

where x in degree-days and y in cubic feet

The predicted amount of gas used when the outside temperature is 17 degree-days is about

y=81+19*17

y=404 cubic feet