Answer
$\approx 2.584$
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:
$\log_{\sqrt5}{8} = \dfrac{\log{8}}{\log{\sqrt5}} \approx 2.584$