Answer
$5.4$
Work Step by Step
Using the properties of logarithms, the given expression, $
\ln e^{5.4}
,$ is equivalent to
\begin{align*}\require{cancel}
&
5.4\ln e
&(\text{use }\log_b x^y=y\log_b x)
\\&=
5.4(1)
&(\text{use }\ln e=1)
\\&=
5.4
.\end{align*}
Hence, the expression $
\ln e^{5.4}
$ evaluates to $
5.4
$.
