math
posted by CLara .
a seismoraph 300km from the epicenter of an earthquake recorded a maximum amplitude of 5.4 x 10^2um. Find this earthquakes magnitude on the Richter Scale. (Round your answer to the nearest tenth). M=

A seismograph 300 km from the epicenter of an earthquake recorded a maximum amplitude of 5.4 102 µm. Find this earthquake's magnitude on the Richter scale. (Round your answer to the nearest tenth.