Answer
$\approx 1.215$
Work Step by Step
$= \log_8 (12.5)$
Since the base of the $\log$ function is not $10$, then the change of base formula is required before evaluating by calculator:
$= \frac{\log 12.5}{\log 8}$
by GDC / calculator
$= 1.2146...$
$\approx 1.215$
