Use Least$-$squares to fit the following data to the equation: y $=$ ao $+$ a$,$ x $+$ a$2$ x$?$

Y

$0$

$1\mathrm{.}1$

$0\mathrm{.}6$

$0\mathrm{.}72$

$1\mathrm{.}0$

$1\mathrm{.}05$

$1\mathrm{.}5$

$1\mathrm{.}7$

$2\mathrm{.}0$

$3\mathrm{.}1$

Find ao$,$ a$1,$ a$,.$

Solve the $3$x$3$ system of equations using MATLAB or any other way.

Show steps of your solution. $($Do not use MATLAB function "polyfit"$)$