On Tuesday 11 March 2008 04:27:12 pm Aad Termorshuizen wrote: AT> # So my QUESTION is: is abline imprecise or am I making errors? Either you are not precise or I did not got your problem. plot(a~b) abline(model) points(10,4336,col="red") as you see the predicted point (red) is exactly at the abline-line. Stefan -- Microeconomics University of Erfurt