Which residual plot would you examine to determine whether the assumption of constant error variance is satisfied for a model with two independent variables $x _ { 1 }$ and $x _ { 2 }$ ?
A) Plot the residuals against observed $y$ values.
B) Plot the residuals against the independent variable $x _ { 2 }$.
C) Plot the residuals against the independent variable $x _ { 1 }$.
D) Plot the residuals against predicted values, $\hat { y }$.

Question

Quizplus · Accepted Answer

Plotting residuals against predicted values ($\hat{y}$) is the standard method to check for constant error variance (homoscedasticity) in a regression model, regardless of the number of independent variables.

Which Residual Plot Would You Examine to Determine Whether the Assumption