Use the Following to Answer Questions :
the Magnitude of an Earthquake

Use the following to answer questions :
The magnitude of an earthquake is given by the equation where I is the actual intensity of the earthquake and I₀ is the reference intensity (the smallest earth movement that can be recorded on a seismograph) .
-Find the value of M(I) when I = 81,500I₀. Round your answer to the nearest tenth.

A) $\approx$ 4.6
B) $\approx$ 4.7
C) $\approx$ 4.8
D) $\approx$ 4.9