\begin{table}%t4
 \caption{\label{12745tb4}Averages of Si, Fe, Ni abundances and Si/Fe, Ni/Fe ratios
 for the cool core cluster sample in solar units. } 
 \small%\centerline
{                   
 \begin{tabular}{l c c}               
\hline\hline                        
{\it mekal} model & & \\
\hline
Metal & mean & scatter  \\
\hline
    Si          & $0.75\pm 0.03$ & $0.22\pm 0.03$ \\
    Si no Cent. & $0.72\pm 0.03$ & $0.17\pm 0.02$ \\
\hline
    Fe          & $0.51\pm 0.02$ & $0.11\pm 0.01$ \\
    Fe no Cent. & $0.49\pm 0.01$ & $0.07\pm 0.01$ \\
\hline
    Ni          & $1.28\pm 0.08$ & $0.45\pm 0.06$ \\
    Ni no Cent. & $1.18\pm 0.07$ & $0.34\pm 0.06$ \\
\hline
 Si/Fe          & $1.47\pm 0.05$ & $0.27\pm 0.05$ \\
 Si/Fe no Cent. & $1.45\pm 0.05$ & $0.30\pm 0.05$ \\
\hline
 Ni/Fe          & $2.41\pm 0.13$ & $0.60\pm 0.12$ \\
 Ni/Fe no Cent. & $2.40\pm 0.14$ & $0.63\pm 0.13$ \\ 
\hline
& & \\
& & \\
\hline\hline                         
{\it apec} model & & \\
\hline
Metal & mean & scatter  \\
\hline
    Si          & $0.83\pm 0.04$ & $0.23\pm 0.03$ \\
    Si no Cent. & $0.80\pm 0.03$ & $0.19\pm 0.03$ \\
\hline
    Fe          & $0.53\pm 0.02$ & $0.12\pm 0.01$ \\
    Fe no Cent. & $0.51\pm 0.01$ & $0.08\pm 0.01$ \\
\hline
    Ni          & $1.07\pm 0.10$ & $0.53\pm 0.07$ \\
    Ni no Cent. & $0.96\pm 0.08$ & $0.39\pm 0.06$ \\
\hline
 Si/Fe          & $1.56\pm 0.05$ & $0.25\pm 0.05$ \\
 Si/Fe no Cent. & $1.56\pm 0.05$ & $0.26\pm 0.05$ \\
\hline
 Ni/Fe          & $1.88\pm 0.14$ & $0.67\pm 0.14$ \\
 Ni/Fe no Cent. & $1.83\pm 0.15$ & $0.67\pm 0.15$ \\
\hline
\end{tabular}} 
\smallskip
Mean values are given
 both for the total sample and with the exclusion of the peculiar Centaurus
 cluster. Average abundance values and intrinsic scatters are computed
 with the maximum likelihood method described in \citet{maccacaro88}.
 \end{table}