Question

The state and local police departments 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 5,150 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 1,030 of the 5,150 residences for data on crime. (Respondents are guaranteed anonymity.) Here are the data collected for the past 12 months for one area:

MONTH	CRIME INCIDENCE	SAMPLE SIZE	CRIME RATE
January	10	1,030	0
February	12	1,030	0
March	10	1,030	0
April	10	1,030	0
May	10	1,030	0
June	12	1,030	0
July	10	1,030	0
August	13	1,030	0
September	12	1,030	0
October	13	1,030	0
November	11	1,030	0
December	11	1,030	0

a. Determine the P−P−, S_p, UCL and LCL for a p-chart of 95 percent confidence (at Z = 1.96). (Round your answers to 5 decimal places.)

P−P−
Sp
UCL
LCL

b. If the next three months show crime incidences in this area as

January = 10 (out of 1,030 sampled)

February = 12 (out of 1,030 sampled)

March = 11 (out of 1,030 sampled)

What comments can you make regarding the crime rate?

	The process is in control.
	The process is out of control.

Answer 1