Answer
$\approx 0.874$
Work Step by Step
RECALL:
The change-of-base formula for logarithms:
$\log_a{b}=\dfrac{\log{b}}{\log{a}}$
Use a calculator and the formula above to obtain:
$\log_{\pi}{e} = \dfrac{\log{e}}{\log{\pi}} \approx 0.874$