Which of the following statements about residuals from the
least squares line are true?
I. The mean of the residuals is always zero.
II. The regression line for a residual plot is a horizontal line.
III. A definite pattern in the residual plot is an indication that a nonlinear model will show a better fit to the data than
the straight regression line.
(A) I and II only
(B) I and III only
(C) II and III only
(D) I, II, and III
(E) None of the above gives the complete set of true