Had a question on a quiz I chose a (I and III) but the teacher said d.(all the above)
Which of the following statements about residuals are true?
I. The means 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 LSRL
I don't think II is correct. If you have three residuals (-1,0,1) then you would have a line threw all three points.
Could someone help me understand what my mistake is? The regression line minimizes the distance between the points and the line, thus with my example (-1,0,1) that fits on a straight line with r =1.