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

Forced expiratory volume (FEV) is the volume of exhaled air and is related to lung size as well as lung function. It is typically lower in persons with impaired lung function due to disease. A regression of height (in inches) on FEV (in liters) showed a nonlinear pattern. Therefore, height was regressed on log(FEV) (natural log) and the residual plot showed a much improved fit. The intercept a and slope b from the regression of height on log(FEV) are a = -2.2 and b = 0.06. The correlation for this regression is:

A) positive.
B) negative.
C) zero.
D) There is not enough information to determine the answer.