Solve the Problem $\mathrm { d } = 1.22 \mathrm { x } ^ { 1 / 2 }$

Solve the problem.
-A formula for calculating the distance, d, one can see from an airplane to the horizon on a clear day is $\mathrm { d } = 1.22 \mathrm { x } ^ { 1 / 2 }$ , where $\mathrm { x }$ is the altitude of the plane in feet and $\mathrm { d }$ is given in miles. How far can one see in a plane flying at 24,000 feet? Round your answer to the nearest tenth mile, if necessary.

A) $189.0 \mathrm { mi }$
B) $1464 \mathrm { mi }$
C) $14,640 \mathrm { mi }$
D) $171.1 \mathrm { mi }$