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 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 800 of the 5,000 residences for data on crime. (Respondents are guaranteed anonymity.) The 800 sampled from each area showed the following incidence of crime during the past month:
AREA NUMBER OF CRIMES SAMPLE SIZE CRIME RATE
1 12 800 0.01500
2 2 800 0.00250
3 17 800 0.02125
4 16 800 0.02000
5 12 800 0.01500
6 24 800 0.03000
7 15 800 0.01875
8 19 800 0.02375
9 10 800 0.01250
10 4 800 0.00500
11 16 800 0.02000
12 13 800 0.01625
13 10 800 0.01250
14 12 800 0.01500
15 14 800 0.01750
16 24 800 0.03000
17 5 800 0.00625
18 16 800 0.02000
19 7 800 0.00875
20 24 800 0.03000
272
a. Determine P, Sp, UCL and LCL for a p chart of 95 percent confidence (at Z = 1.96).
b. What can you say about the process?