 |
 |
At 21:10 14/06/01, you wrote: >A friend of mine has asked for help with the following problem: > >Suppose a scatter diagram has perfect positive correlation and the graph is >linear. Is there a proof that the equation of the line is y = a + bx? Hi Paul (and list), Its a tricky one to see exactly what you mean. I would guess that one approach would be to calculate the predicted values, based on the equation y = a + bx, and then plot the values of y against the predicted values, based on the equation. The plot would be a straight line, and the correlation (if you calculated it) would be 1.00, showing that the equation gives perfect prediction of the values of y in the data. However, you are then (re) using the equation, and are stuck in a circular argument, because proving that y = a + bx requires believing that y = a + bx. Maybe that will help anyway, JM ---------- Dr Jeremy Miles [log in to unmask] Phone: 01332 592090, Fax: 01332 593131, Mobile: 07941 228018 Inst. of Behavioural Sciences, Derby University, Derby, DE22 3HL, UK http://ibs.derby.ac.uk/~jeremym / http://www.jeremymiles.co.uk NOTE: After 1st August, 2001, Department of Health Sciences, University of York, Heslington, York, YO10 5DD