A thin stick is placed along the $x$ axis so that one of its ends is at $x_{1}0\mathrm{.}00m$ and the other one at $x_2=2\mathrm{.}45m.$ The stick has a non$-$uniform mass density $(x)=ax+b,$ where $a=0\mathrm{.}609k\frac{g}{m^2}$ and $b=1\mathrm{.}672k\frac{g}{m}.$

What is the $x$ coordinate $x_{cm}$ of the stick's center of mass?

$x_{cm}=$