Suppose X 50, SX 10, Y 200, and SY 30. What is the value of r for each of the following circumstances?
(a) For X 40, the regression equation predicts Y 170.
(b) For X 40, the equation predicts Y 230.
(c) For X 60, Y 215.
(d) For X 30, Y 230.
(e) For X 70, Y 215.