In the residual by predicted plot below, we see that the residuals are randomly scattered around the center line of zero, with no obvious non-random pattern. The normal quantile plot of the residuals gives us no reason to believe that the errors are not normally distributed. ...
If the conditional residuals are normally distributed, the points on the normal quantile plot should approximately fall along the red diagonal line. This type of plot is also called a quantile‐quantile plot, or Q‐Q plot. The normal quantile plot also shows Lilliefors confidence bounds (Conover...