Answer
$\dfrac{1}{2}$
Work Step by Step
Recall:
$\log_a{\left(a^n\right)}=n$
Using the rule above, and knowing the natural logarithms has base $e$, gives:
\begin{align*}
\dfrac{\ln{\left(e^4\right)}}{8}&=\dfrac{\log_e{\left(e^4\right)}}{8}\\\\
&=\dfrac{4}{8}\\\\
&=\dfrac{1}{2}
\end{align*}