## Q. 3.24

Roller Coasters

The mean speed for the five fastest wooden roller coasters is 69.16 miles per hour, and the variance is 2.76. The mean height for the five tallest roller coasters is 177.80 feet, and the variance is 157.70. Compare the variations of the two data sets.

Source: Ultimate RollerCoaster.com

## Verified Solution

\begin{aligned}\text { CVar } & =\frac{\sqrt{2.76}}{69.16} \cdot 100 \approx 2.4 \% \\\text { CVar } & =\frac{\sqrt{157.70}}{177.80} \cdot 100 \approx 7.1 \%\end{aligned}

The variation in the speeds is slightly larger than the variation in the heights of the roller coasters.