[填空题]
A student measures a length five times.mb: dcip*t qp:u6u(jm1z yku lei( q(4hdq.:2 All/j()h, hxxrib 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 $cm$ (Do not include the $\pm$ symbol nor the unit)
