[填空题]
A student measures a l6j vs):rduh: )/ n ,ma+gevx knxb-1dlength five times. All of the; ggk*)mbw53wp 9ce up 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.)