\tiny\arraycolsep .95ex
\begin{array}{|c|cccccccccc|}
\multicolumn{11}{c}{\mbox{\large \bf Test de valores atípicos}}\\
\multicolumn{11}{c}{\mbox{\normalsize \bf Valores críticos}}\\
\hline
&\multicolumn{10}{|c|}{n}\\ \hline
\alpha&5& 10& 15& 20& 25& 50& 75& 100& 200& 500\\ \hline
0'05&2'9& 3'9& 4'1& 4'1& 4'0& 3'99& 3'87& 3'77& 3'57& 3'37\\
0'01&3'1& 4'8 &5'1 &5'2& 5'0& 4'88& 4'59& 4'39& 3'98& 3'60\\
\hline
\end{array}