Answer
$2.584$
Work Step by Step
Change of Base Formula: $\hspace{20pt} \log_ a M = \dfrac{\log_b M}{\log_b a}$
$\log_{\sqrt{5}} 8= \dfrac{\log_{10} 8}{\log_{10} \sqrt{5}}$
Where: $a=\sqrt{5} \hspace{10pt} M = 8 \hspace{10pt} b = 10$
$ \dfrac{\log_{10} 8}{\log_{10} \sqrt{5}} \approx \boxed{2.584}$