TDSM 9.1

This set of points has the regression line y = x:

   (0, 1),
   (0, -1),
   (1, 0),
   (1, 2),
   (2, 1),
   (2, 3),
   (-1, 0),
   (-1, -2),
   (-2, -1),
   (-2, -3)