Answer
Does not make sense.
Work Step by Step
See example 9 on p.463
The magnitude R of an earthquake of intensity I is given by
$R=\displaystyle \log\frac{I}{I_{0}},$
where $I_{0}$ is a zero-level earthquake.
For R=8, (apply $10^{(...) }$to the above formula)
$\displaystyle \frac{I_{8}}{I_{0}}=10^{8}$
$I_{8}=10^{8}I_{0}$ (the intensity was $10^{8}$ of the zero-level intensity.
For R=4, $I_{4}=10^{4}I_{0}.$
The ratio of the two intensities is
$\displaystyle \frac{I_{8}}{I_{4}}=\frac{10^{8}I_{0}}{10^{4}I_{0}}=10^{8-4}=10^{4}$
so
$I_{8}=10,000I_{4}$
The magnitude 8 earthquake has 10,000 times the intensity of the magnitude 4 earthquake (not twice, but 10,000 times as intense).
