Code: Select all
\begin{table}[h!]
\caption{Medidas para la obtención del diámetro del disco de Airy}
\centering
\begin{tabular}{c c c c} % centered columns (4 columns)
\hline\hline
% inserts double horizontal lines
$x'_1 \pm \varepsilon(x'_1)(mm)$ & $x'_2 \pm \varepsilon(x'_2)(mm)$ & $ H\pm\varepsilon(H)(mm)$ & $ \bar H\pm\varepsilon(\bar H)(mm)$\\
\hline % inserts single horizontal line
$0 \pm 0.01$ & $1.21\pm 0.01$ &$1.21\pm 0.01$ & $1.19\pm 0.02$\\ % inserting body of the table
$0 \pm 0.01$ & $1.15\pm 0.01$ & $1.15\pm 0.01$\\
$0 \pm 0.01$ & $1.20\pm 0.01$ & $1.20\pm 0.01$\\
\hline %inserts single line
\end{tabular}
\end{table}