#### Answer

$x\approx5.021$

#### Work Step by Step

In exponential form, the given logarithmic equation, $
\ln (4x) =3
,$ is equivalent to
\begin{array}{l}\require{cancel}
\log_e (4x) =3
\\\\
4x=e^3
.\end{array}
Hence, the value of the variable that satisfies the given equation is
\begin{array}{l}\require{cancel}
x=\dfrac{e^3}{4}
\\\\
x\approx5.021
.\end{array}