\begin{table}%t1 
\caption {\label{parametry-T90}Parameters of the best $\chi^2$ fits of
two and three log-normal functions on the RHESSI GRB~$T_{90}$ distribution.
$\mu$ are the means, $\sigma$ are the standard deviations
and~$w$ are the weights of the distribution.
Given uncertainties are standard deviations of the parameters
obtained by ten different fittings of randomly changed histogram of durations
by their uncertainties.}
%\centering
\par
\begin{tabular}{lrr}
\hline\hline
%\\[-2ex]
Parameter                    &    2 log-normal  &  3 log-normal  \\[0.3ex]
\hline
%\\[-2ex]
$\mu_{{\rm short}}$       &     --0.46~$\pm$~0.13   &  --0.68~$\pm$~0.09  \\[0.3ex]
$\sigma_{{\rm short}}$    &      0.60~$\pm$~0.06   &   0.20~$\pm$~0.03  \\[0.3ex]
$w_{{\rm short}}[\%]$     &     18.7~$\pm$~1.5     &   8.9~$\pm$~1.0    \\[0.3ex]
%\\[-2ex]
$\mu_{{\rm long}}$        &      1.26~$\pm$~0.03   &  1.27~$\pm$~0.03  \\[0.3ex]
$\sigma_{{\rm long}}$     &      0.42~$\pm$~0.01   &  0.41~$\pm$~0.01  \\[0.3ex]
$w_{{\rm long}}[\%]$      &      81.3~$\pm$~1.5    &  83.4~$\pm$~0.9    \\[0.3ex]
%\\[-2ex]
$\mu_{{\rm middle}}$      &                  &  0.17~$\pm$~0.06 \\[0.3ex]
$\sigma_{{\rm middle}}$   &                  &  0.27~$\pm$~0.06 \\[0.3ex]
$w_{{\rm middle}}[\%]$    &                  &   7.7~$\pm$~1.0   \\[0.3ex]
%\\[-2ex]
$\rm d.o.f.$                        &          14      &            11    \\[0.3ex]
$\chi^2$                     &          19.13   &            10.30 \\[0.3ex]
goodness[\%]                 &          16.0    &            50.4  \\[0.3ex]
\\[-2ex]
$ F_{0} $                    &          3.14    &                  \\[0.3ex]
$P(F>F_{0})[\%] $            &           6.9    &                  \\
\hline
\end{tabular}
\end{table}