[填空题]
A student measures a length 1v)f; on3 e2,g qgesgafjv4u wjee.-9z1hk 2s)v/qat o ive times. All of the measurements 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.)