\[\boxed{\mathbf{1131}\mathbf{.}\mathbf{\ }}\]
\[1)\ \frac{7}{11} \Longrightarrow \frac{11}{7}\]
\[2)\ 6 \Longrightarrow \frac{1}{6}\]
\[3)\ 2\frac{2}{5} = \frac{12}{5} \Longrightarrow \frac{5}{12}\]
\[4)\ \frac{1}{9} \Longrightarrow 9\]