The State Highway Patrol (SHP) periodically samples vehicle speeds at Milepost 92 on Interstate 17. The SHP is concerned about the dispersion of speeds of vehicles sharing the same highway because significant difference in speed is a known cause of accidents. The speeds of a random sample of 16 vehicles are shown below.
$$\begin{array} { l l l l l l l l l }
\text { Vehicle } & 1 & 2 & 3 & 4 & 5 & 6 & 7 & 8 \
\text { Speed } & 69.6 & 73.5 & 74.1 & 64.4 & 66.3 & 68.7 & 69.0 & 65.2 \
\hline \text { Vehicle } & 9 & 10 & 11 & 12 & 13 & 14 & 15 & 16 \
\text { Speed } & 71.1 & 70.8 & 64.6 & 67.4 & 69.9 & 66.3 & 68.3 & 70.6
\end{array}$$ The SHP's policy is to position a patrol car at Milepost 92 on Interstate 17 if the vehicle speed variance at that location is believed to be greater than 6 mph. Conduct a hypothesis test (with a = .10) to determine whether the speed variance for all vehicles passing Milepost 92 exceeds 6 mph.

Question

The State Highway Patrol (SHP) periodically samples vehicle speeds at Milepost 92 on Interstate 17. The SHP is concerned about the dispersion of speeds of vehicles sharing the same highway because significant difference in speed is a known cause of accidents. The speeds of a random sample of 16 vehicles are shown below.
​ $$\begin{array} { l l l l l l l l l } 
\text { Vehicle } & 1 & 2 & 3 & 4 & 5 & 6 & 7 & 8 \
\text { Speed } & 69.6 & 73.5 & 74.1 & 64.4 & 66.3 & 68.7 & 69.0 & 65.2 \
\hline \text { Vehicle } & 9 & 10 & 11 & 12 & 13 & 14 & 15 & 16 \
\text { Speed } & 71.1 & 70.8 & 64.6 & 67.4 & 69.9 & 66.3 & 68.3 & 70.6
\end{array}$$ The SHP's policy is to position a patrol car at Milepost 92 on Interstate 17 if the vehicle speed variance at that location is believed to be greater than 6 mph. Conduct a hypothesis test (with a = .10) to determine whether the speed variance for all vehicles passing Milepost 92 exceeds 6 mph.

Quizplus · Accepted Answer

The Answer of The State Highway Patrol (SHP) periodically samples vehicle speeds at Milepost 92 on Interstate 17. The SHP is concerned about the dispersion of speeds of vehicles sharing the same highway because significant difference in speed is a known cause of accidents. The speeds of a random sample of 16 vehicles are shown below.
​ $$\begin{array} { l l l l l l l l l } 
\text { Vehicle } & 1 & 2 & 3 & 4 & 5 & 6 & 7 & 8 \
\text { Speed } & 69.6 & 73.5 & 74.1 & 64.4 & 66.3 & 68.7 & 69.0 & 65.2 \
\hline \text { Vehicle } & 9 & 10 & 11 & 12 & 13 & 14 & 15 & 16 \
\text { Speed } & 71.1 & 70.8 & 64.6 & 67.4 & 69.9 & 66.3 & 68.3 & 70.6
\end{array}$$ The SHP's policy is to position a patrol car at Milepost 92 on Interstate 17 if the vehicle speed variance at that location is believed to be greater than 6 mph. Conduct a hypothesis test (with a = .10) to determine whether the speed variance for all vehicles passing Milepost 92 exceeds 6 mph.

The State Highway Patrol (SHP) Periodically Samples Vehicle Speeds at Milepost