[填空题]
A student measures a length five timeg9k5po:jm b1is. All of thet;6e2;tx3olct nx )fk b2p*yo 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.)