Chapter 9 - Section 9.3 - Logarithmic Functions and Models - Exercises - Page 659: 65e

(blank)= $1000$

By the result of (d) $\displaystyle \frac{E_{2}}{E_{1}}=10^{1.5(R_{2}-R_{1})}$ If $R_{2}=R_{1}+2$ then $\displaystyle \frac{E_{2}}{E_{1}}=10^{1.5(R_{1}+2-R_{1})}=10^{3}=1000$ The second earthquake releases $1000$ times the amount of energy of the first quake.