1. Suppose X 55, SX 12, Y 118, and SY 27. For a case that stands at 55 on X, the regression equation predicts that Y118. Can you tell the value of r? Explain.
2. According to the regression equation for a particular problem in prediction, when X 81, Y317; when X 84, Y317; and when X 92, Y 317.
(a) What is the value of r? How can you tell?
(b) What is Y? How can you tell?
(c) Can you infer the value of X ? Explain.