Look at the columns Y (actual Y) and Y (estimated Y) values. Plot the two in a scatter gram. What does the scatter gram reveal? If you believe that the fitted model [Eq. (2.20)] is a "good" model, what should be the shape of the scatter gram? In the next chapter we will see what we mean by a "good" model.
For Information: Refer to the math S.A.T. score example discussed in the text. Table 2-4 gives the necessary raw calculations to obtain the OLS estimators.