Problem 4 (25 points). Consider the 4 points (2,2), (0,0), (1,2), (2,0). a) Write the (overdetermined) linear system Am = b arising from the linear regression problem (i.e., t a straight line). b) [MATLAB] Determine a thin QR factorization of the system matrix A. c) [MATLAB] Use the factorization to solve the linear regression (least-squares) problem. d) [MATLAB] Plot the regression line