Sonora County Sherriff Case 7.1 (pg. 195/6)
Sonora County is located in northern California and is known for its wine country and rugged Pacific coastline. Sonora is a rural county with only one major city, Santa Rita, which has a population of approximately 150,000. Sonora State University is located in Santa Rita and has a student population of approximately 12,000. The county sheriff keeps a monthly record of her department’s law enforcement activities by incident as shown in Figure 7.13 below for the prior year. She is troubled by an apparent recent increase in burglaries.
As the administration manager for the sheriff’s office you need to:
- Prepare a run chart on each of the incident categories. Does she have reason to be concerned about burglaries? What variable might you plot against burglaries to create a scatter diagram to determine a possible explanation?
- What is unusual about the pattern of reported disorderly and DUI incidents by month? What could be an explanation for this behavior? How could the sheriff address this pattern and reduce the number of incidents?
- Would you recommend preparing control charts for assault and theft incidents? Why or why not?
- Prepare a Pareto chart based on the total of last year’s incidents. Why might the sheriff not prioritize efforts on incident reduction according to the results of the Pareto chart?
