Forced expiratory volume (FEV) is the volume of exhaled air, and it is related to lung size as well as to lung function. FEV is typically lower in persons with impaired lung function due to disease. The residual plots below are from two regressions: the first plot is from regressing height on FEV and the second is from regressing height on log(FEV). Based on these plots, which statement is correct?
A)The residual plot for height on FEV shows a nonconstant variance.
B)The residual plot for height regressed on FEV shows a nonlinear pattern.
C)The residual plot for the regression of height on log(FE
V)shows a linear pattern.
D)All of the answer options are correct.

Question

Forced expiratory volume (FEV) is the volume of exhaled air, and it is related to lung size as well as to lung function. FEV is typically lower in persons with impaired lung function due to disease. The residual plots below are from two regressions: the first plot is from regressing height on FEV and the second is from regressing height on log(FEV).   Based on these plots, which statement is correct?
A)The residual plot for height on FEV shows a nonconstant variance. 
B)The residual plot for height regressed on FEV shows a nonlinear pattern. 
C)The residual plot for the regression of height on log(FE
V)shows a linear pattern. 
D)All of the answer options are correct.

Quizplus · Accepted Answer

The residual plot for height on FEV shows a nonconstant variance, indicating that the variability of the residuals changes across the range of FEV values. The residual plot for height regressed on FEV shows a nonlinear pattern, indicating that a linear model may not be appropriate for the data. The residual plot for the regression of height on log(FEV) shows a linear pattern, indicating that a linear model is appropriate for this regression. Therefore, all of the answer options are correct.

Forced Expiratory Volume (FEV) Is the Volume of Exhaled Air