The following correlation matrix shows the pairwise correlations among three variables: two explanatory variables X1 and X2 and the response denoted by Y. For example, corr(Y, X2) = 0.2359.

(a) Why does it make sense to put 1s down the diagonal of this table?
(b) Find the slope of the simple regression of Y on X1, if you can. If you cannot, indicate what€™s missing.
(c) Do you think that the marginal slope for Y on X2 will be similar to the partial slope for X2 in the multiple regression of Y on X1 and X2?

Y 1.0000 0.8667 0.2359 X1 0.8667 1.0000 0.0000 X2 0.2359 0.0000 1.00000