Chapter 5.4, Problem 24E

Find the least-squares solution $\stackrel{\to }{x}*$ of the system
$A\stackrel{\to }{x}=\stackrel{\to }{b}$ , where $A=\left[\begin{array}{l}1\\ 2\\ 3\end{array}\right]$ and $\stackrel{\to }{b}=\left[\begin{array}{l}3\\ 2\\ 7\end{array}\right]$ .
Draw a sketch showing thevector $\stackrel{\to }{b}$ , the image of A, thevector $A\stackrel{\to }{x}*$ , and the vector $\stackrel{\to }{b}-A\stackrel{\to }{x}*$ .