Q. The state and local police departments at I-STATE are trying to analyze crime rates so they can shift their patrols from decreasing-rate areas to areas where rates are increasing. The city and county have been geographically segmented into areas containing 5,000 residences. The police recognize that not all crimes and offenses are reported: People do not want to become involved, consider the offenses too small to report, are too embarrassed to make a police report, or do not take the time, among other reasons. Every month, because of this, the police are contacting by phone a random sample of 1,000 of the 5,000 residences for data on crimes. (Respondents are guaranteed anonymity.) Please find the crime data collected for the past 12 months for one area.

Month Crimes Sample Size

January 7 1000

February 9 1000

March 7 1000

April 7 1000

May 7 1000

June 9 1000

July 7 1000

August 10 1000

September 8 1000

October 11 1000

November 10 1000

December 8 1000

Construct a p-chart for 95% confidence (2 sigma) and plot each of the months. If the next three months show crime incidences in the area as

January = 10 (out of 1,000 sampled);

February = 12 (out of 1,000 sampled);

March = 11 (out of 1,000 sampled).

1) What comments can you make regarding the crime rate?

The governor of I-STATE had to be comfortable with the reality that crime in a such a diverse state cannot be zero. This is not the "Good Place" sitcom, her inner voice said. She still felt it was useful to set some goals for tracking for the purposes of planning law enforcement and other support services. She set a target crime rate of 1.5% with a tolerance of 0.5%. She would like to shoot for 2-sigma capability.

2) Given the dataset you have analyzed, is I-STATE 2-sigma capable? If not, explain why and what the governor can do to make the process capable.

A neighboring governor was bragging at a meeting that his state had essentially zero crime.

3) The I-STATE governor was suspicious because the neighboring state was using reported crimes. She wanted to propose to her senator to standardize the measurement of crime rate across states. She wondered if a robust strategy was to randomly survey residents via phone, as currently done at I-STATE. An obvious criticism is that this approach does not use the reported crimes data. Is there a way to combine reported crime data with the random survey data to improve the quality of crime measurements?

4) The I-STATE governor also knew that she needed to act locally in the spirit of continuous improvement. She wondered whether she should change her target to be closer to zero or shoot for 3-sigma capability. Given the dataset that you have analyzed, which strategy would be more appropriate?