Question

Problem 10-28

Some citizens complained to city council members that there should be equal protection under the law against the occurrence of crimes. The citizens argued that this equal protection should be interpreted as indicating that high-crime areas should have more police protection than low-crime areas. Therefore, police patrols and other methods for preventing crime (such as street lighting or cleaning up abandoned areas and buildings) should be used proportionately to crime occurrence.

         The city has been broken down into 20 geographic areas, each containing 4,800 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 960 of the 4,800 residences for data on crime. (Respondents are guaranteed anonymity.) The 960 sampled from each area showed the following incidence of crime during the past month:

AREA	NUMBER OF CRIMES	SAMPLE SIZE	CRIME RATE
1	18	960	0.019
2	2	960	0.002
3	13	960	0.014
4	12	960	0.013
5	16	960	0.017
6	16	960	0.017
7	13	960	0.014
8	13	960	0.014
9	6	960	0.006
10	3	960	0.003
11	22	960	0.023
12	14	960	0.015
13	18	960	0.019
14	8	960	0.008
15	4	960	0.004
16	12	960	0.013
17	4	960	0.004
18	18	960	0.019
19	6	960	0.006
20	12	960	0.013
	230

a. Determine P−P−, S_p, UCL and LCL for a p chart of 95 percent confidence (at Z = 1.96). (Round your answers to 4 decimal places.)

P−P−
Sp
UCL
LCL

b. What can you say about the process?

	Process is in statistical control.
	Process is out of statistical control.

Answer 1