Question

What two plots did we use in this chapter to decide whether we can reasonably presume that the assumptions for regression inferences are met by two variables of a population? What properties should those plots have?

Short answer

Residual plot and Normal Probability_plot

Step-by-step solution

Step 1:Given information

Given two plots

Step 2:Explaination

Residual plot: A plot of the residuals against the observed values of the predictor variable. It represents a plot of the residuals against the observed values of the predictor variable should roughly in a horizontal band and it is centered and symmetric about the $x$-axis.

Normal Probability_plot: A normal probability plot of the residuals should be roughly linear.