Least squares

Consider the least squares problem with:$$X= \begin{pmatrix} 1 & -2 & 1 \\ 1 & 1 & 2 \\ 1 & 3 & 0 \\ 1 & 0 & 1 \\ \end{pmatrix} \qquad \mathbf{y}= \begin{pmatrix} -2 \\ 0 \\ 3 \\ 2\end{pmatrix}$$The pseudoinverse is given by:

$$X^{\dag}= \frac{1}{22} \begin{pmatrix} 13 & -10 & 12 & 7 \\ -5 & 3 & 3 & -1 \\ -5 & 14 & -8 & -1 \\ \end{pmatrix}$$Compute the error with two decimal places