Question 1: Consider the model Yi = ,3.) + lXi + 15,-, where 61,. . .,,, are identical and independently distributed 1with mean 1] and variance :12. Let the observed data be (:31, yl), . . . , (12,1, 3;\"). Substituting the data into the mode] and presented in terms of matrices, we have s = XE + - 3. State the designed matrix X in terms of the observed data. b. I{Jibtsin X'X, {X'X}_1, and X'y