The graph below shows the relationship between the amount of KWH of energy produced each month by a solar panel installed on Building 16 at Lummi campus, and the net electrical bill for that building in the same month.

a) Describe the correlation shown in the scatterplot. (positive or negative?)

b) In this context, interpret the slope and the y-intercept of the regression line. (You should say what these numbers say about the amount of energy produced by solar panels and the net electrical bill.)

c) Use the formula for the regression line to predict the net electrical bill if the amount of energy produced by the solar panel is 730 KWH. How confident would you feel in making the prediction?

d) Use the formula for the regression line to predict the net electrical bill if the amount of energy produced by the solar panel is 2000 KWH. How confident would you feel in making the prediction?

140 120 y =-0.1x + 124.6 100 | 80 60 40 D 20 The formula of the regression line. 200 400 600 800 1000 20 40 60 KWH of energy produced by solar panels