Answer
$\color{blue}{s\approx 11.9 \text{ mi}}$
Work Step by Step
RECALL:
The length of the arc $(s)$ intercepted by the central angle $\theta$ in a circle of radius $r$ is given by the formula:
$s = r\theta$, where $\theta$ is in radian measure.
Use the formula above to obtain:
$s=r\theta
\\s=3.24\cdot \frac{7\pi}{6}
\\s=11.87522023
\\\color{blue}{s\approx 11.9 \text{ mi}}$