[填空题]
A student measures a lehe9h ajfv+5q /s-s ugz/*t-+1f ngheangth five times. All of the measuremea-ee7 w .rw2hcnts lie between $18.8 \mathrm{~cm}$ 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.)