[填空题]
A student measures a length five timesyun t:h)x a f:q:)* mvg(6zffz. All of the measurements lie 407h c xfkyueg4 xg*)lbetween $18.8 \mathrm{~cm}$ and $19.2 \mathrm{~cm}$. What should the student quote as the absolute uncertainty in the length? The absolute uncertainty is $cm$ (please only input numerical value without units and without the $\pm$ symbol.)