A solid is formed by rotating the region bounded by the curve $y=e^{-4 x/2}$ and the $x$-axis between $x=0$ and $x=1$, around the $x$-axis. The volume of this solid is ${\pi\over 4}\cdot (1 - e^{-4})$. Assuming the solid has constant density $\delta$, find $\bar x$ and $\bar y$.

$\overline x =$
$\overline y =$