The race speeds (in minutes)for the top eight cars in a 200-mile race are listed below. Use the range rule of thumb to estimate the standard deviation. Round results to the nearest tenth. $\begin{array}{llllllll}
181.0 & 180.6 & 189.2 & 182.2 & 175.6 & 180.0 & 177.9 & 181.8
\end{array}$

A)1.1 minutes
B)6.8 minutes
C)7.5 minutes
D)3.4 minutes

Question

The race speeds (in minutes)for the top eight cars in a 200-mile race are listed below. Use the range rule of thumb to estimate the standard deviation. Round results to the nearest tenth. $\begin{array}{llllllll}
181.0 & 180.6 & 189.2 & 182.2 & 175.6 & 180.0 & 177.9 & 181.8
\end{array}$

A)1.1 minutes
B)6.8 minutes
C)7.5 minutes
D)3.4 minutes

Quizplus · Accepted Answer

The range rule of thumb estimates the standard deviation as the range of the data set divided by 4. The range is the difference between the maximum and minimum values: 189.2 - 175.6 = 13.6. Dividing this by 4 gives 3.4, so the estimated standard deviation is 3.4 minutes.

The Race Speeds (In Minutes)for the Top Eight Cars in a 200-Mile