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. $$\begin{array} { l l l l l l l l }
181.0 & 180.6 & 189.2 & 182.2 & 175.6 & 180.0 & 177.9 & 181.8
\end{array}$$
A) 7.5 minutes
B) 6.8 minutes
C) 3.4 minutes
D) 1.1 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. $$\begin{array} { l l l l l l l l } 
181.0 & 180.6 & 189.2 & 182.2 & 175.6 & 180.0 & 177.9 & 181.8
\end{array}$$
A) 7.5 minutes
B) 6.8 minutes
C) 3.4 minutes
D) 1.1 minutes

Quizplus · Accepted Answer

The range rule of thumb estimates the standard deviation as the range divided by 4. The range is 189.2 - 175.6 = 13.6. Dividing by 4 gives 3.4.

The Race Speeds (In Minutes) for the Top Eight Cars 181.0180.6189.2182.2175.6180.0177.9181.8\begin{array} { l l l l l l l l } 181.0 & 180.6 & 189.2 & 182.2 & 175.6 & 180.0 & 177.9 & 181.8\end{array}181.0​180.6​189.2​182.2​175.6​180.0​177.9​181.8​

The Race Speeds (In Minutes) for the Top Eight Cars $\begin{array} { l l l l l l l l } 181.0 & 180.6 & 189.2 & 182.2 & 175.6 & 180.0 & 177.9 & 181.8\end{array}$