Precalculus one math

Question

The 1906 San Francisco earthquake had a magnitude of 7.9 on the MMS scale. Around the same time there was an earthquake in South America with magnitude 6.7 that caused only minor damage. How many times more intense was the earth movement in San Francisco earthquake than the South American one? 

Answer 1

I am guessing a little bit here.

try. 10^(7.9)/10^(6.7) =. 15.84893192

which is the same as 10^(1.2)

good luck