Graphical display of the equation

The linear equation to predict a response from a single explanatory variable can be displayed as a straight line on a scatterplot of Y against X.

y  =  b0 + b1 x

The corresponding equation for predicting Y from X and Z is

y  =  b0 + b1 x + b2 z

and it can be displayed as a plane on a 3-dimensional scatterplot of Y against X and Z.

Body fat