Chapter 6 - Logarithmic Functions - Chapter Review Exercises - Page 542: 43

$I=50.12$ cm

$M=5.7$ $S=10^{-4}$ cm Putting in the equation $M=\log\frac{I}{S}$ $5.7=\log\frac{I}{10^{-4}}$ $5.7=\log(10^4 I)$ $10^4 I=10^{5.7}$ $I=\frac{10^{5.7}}{10^4}$ $I=10^{1.7}\approx 50.119$ Correct to two significant digits $I=50.12$ cm