The residual plots from five different least squares regression lines are shown below. Which of the plots provides the strongest evidence that its regression line is an appropriate model for the data and is consistent with the assump- tions required for inference for regression?

There are four assumptions. Since the graphs don't show the values for \(Y\), we can only really check that the assumption that the variance of the residuals is uniform regardless of the value of \(X\). We should therefore expect similar variance in the residuals for any given \(X\) value. Only one plot corresponds to this assumption.

The last plot might seem like an okay choice, but its variance decreases with larger values of \(X\).