The factor of intensity increase for each whole number increase in the Richter scale is 10. This is because the Richter scale is a logarithmic scale that has a base of 10. As an example, a Richter scale of 1 increased to 2 will have an intensity increase of 10^2 / 10^1 = 10
For example, an earthquake with magnitude 2 is 102 times more intense than a standard earthquake, while an earthquake with magnitude 3 is 103 times more intense than a standard earthquake, and 103 = 102 × 10.
You would divide the 2/3 by 4 which would be 1.6 recurring and then put that back into a fraction which would be 1/6. I'm not sure if his is correct but this what is learnt ♡♡chyna