Chapter 6 - Logarithmic Functions - 6.6 Solving Logarithmic Equations - 6.6 Exercises - Page 534: 14

$M= 7.5+2=9.5$

$I=316227.77$cm $S=10^{-4}$cm $M=\log \frac{I}{S} $ Putting the values of $I$ and $S$ . $M=\log\frac{316227.77}{10^{-4}}$ $M=\log(316227.77\times10^4)$ $M=\log(31622777\times10^2)$ $M=\log31622777+\log10^2$ $M=\log31622777+2\log10$ $M=\log31622777+2$ $M= 7.5+2=9.5$