Answer
$5.2340$
Work Step by Step
Apply the Change of base property: $\displaystyle \quad \log_{b}M=\frac{\log_{a}M}{\log_{a}b}$
Change to base 10 (common logarithm)
$\displaystyle \log_{\pi}400=\frac{\ln 400}{\ln\pi}\approx 5.2340$
You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.