144 Passive exposure to smoke (continued). Refer to Exercise 143 . Two MINITAB residual plots for the simple linear regression model are shown below.

a. Which graph should be used to check for normal errors? Does the assumption of normality appear to be satisfied?

b. Which graph should be used to check for unequal error variances? Does the assumption of equal variances appear to be satisfied?

Transcribed Image Text:

Residual Percent 60 40 20 -20- 30 -50 Normal Probability Plot of the Residuals (response is WtPctile). 25 50 Residual Residuals Versus the Fitted Values (response is WtPctile) 32 34 36 Fitted Value 38 40