[填空题]
A student measures a length five times. All of the meas 1 alq(vidyin693 h)eu( 6ojxzuremenfnu8vn ,*mq4:++ bhg7t u sp1t9hxyfnts 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.)