Answer
4
Work Step by Step
Based on the definition of the natural logarithm, we know that $ln(x)=log_{e}x$.
Furthermore, recall that $log_{b}x=y$ is equivalent to the statement $b^{y}=x$ (where $x\gt0$, $y$ is a real number, and $b\gt0$ and $b\ne1$).
Therefore, $ln(e^{4})=log_{e}e^{4}=4$, because $e^{4}=e^{4}$.