Question:
If $f(c)=\frac{3}{2c-3}$, find $\frac{kn^2}{lm}$ when $f^{-1}(c)\times c \times f(c)$ equals the simplified fraction$\frac{kc+l}{mc+n}$, where $k,l,m,\text{ and }n$ are integers.

Answer:
Apply the definition of $f$ to the identity $f(f^{-1}(c))=c$ to find \begin{align*}
c&=\frac{3}{2f^{-1}(c)-3}\quad\Rightarrow\\
c(2f^{-1}(c)-3)&=3\quad\Rightarrow\\
2f^{-1}(c)-3&=\frac{3}{c}\quad\Rightarrow\\
2f^{-1}(c)&=\frac{3}{c}+3\quad\Rightarrow\\
f^{-1}(c)&=\frac{3}{2c}+\frac{3}{2}\quad\Rightarrow\\
&=\frac{3}{2}\left(\frac{1}{c}+1\right).
\end{align*}Therefore, $f^{-1}(c)\times c \times f(c)$ can be found: \begin{align*}
f^{-1}(c)\times c \times f(c)&=\left(\frac{3}{2}\left(\frac{1}{c}+1\right)\right)\times c \times \frac{3}{2c-3}\quad\Rightarrow\\
&=\frac{3}{2}\times\frac{1+c}{c}\times c \times\frac{3}{2c-3}\quad\Rightarrow\\
&=\frac{3\times (1+c)\times 3}{2 \times (2c-3)}\quad\Rightarrow\\
&=\frac{9+9c}{4c-6}\quad\Rightarrow\\
&=\frac{9c+9}{4c-6}.
\end{align*}Thus, $k=9$, $l=9$, $m=4$, and $n=-6$. So, $\frac{kn^2}{lm}=\frac{9\times(-6)^2}{9\times 4}=\boxed{9}$.