\begin{table}%t4
%\centering
\par
\caption{Slopes of the linear fits to the logarithm of the mean weighted PWTs
for sub-samples of the analysed stars and without any
correction for the magnitude of
the stars. }
%\begin{center}
\par
\begin{tabular}{c c c} \hline \hline\noalign{\smallskip}
 Spectral & Slope from $1.0\times 10^{-4}$ & Slope from $0.7\times 10^{-3}$ \\
 type & to $0.6\times 10^{-3}$ Hz  & to $2.5\times 10^{-3}$ Hz \\ \hline
 F & $-0.618  \pm 0.021 $&    $ -0.519\pm 0.006$ \\
 G & $-0.561  \pm 0.017 $&    $ -0.419\pm 0.007$ \\
 K & $-0.639  \pm 0.023 $&    $ -0.573\pm 0.013$ \\
 M & $-0.653  \pm 0.018 $&    $ -0.582\pm 0.007$ \\ \hline
\par
\end{tabular}
%\end{center}
\par
\end{table}