Theft Cases in 2007 and 2008: Is There any Significant Change
Human society is faced with criminal activities of different kinds like theft, burglary, robbery, robbery, arson, rape, assault, murders etc. All these are unpleasant and something none of us will like, but unfortunately, we all have to live with it and learn to cope with it. To minimize and control these unpleasant occurrences there is police. Police has mandate to ensure a safe life for citizens by controlling and minimizing occurrence of criminal activities, which is evident from reduced criminal cases year after year. The data on criminal cases are logged and a suitable statistical analysis ...view middle of the document...
To determine this one can perform correlation or regression analysis. Many times data on a variable is measured over different periods of time or under different experimental conditions and then the interest is in knowing whether there exists a significant difference in the value of the variable under different experimental conditions or different periods of time. To know this one need to perform a hypothesis test. In hypothesis test one starts with the null hypothesis that there exists no significant difference in the mean value of the variable under the conditions or time periods in the study and an alternative hypothesis that one of the means is significantly smaller and / larger (depends on the problem) than the other mean. This hypothesis is tested using suitable statistics (z-statistics, t-statistics, F-statistics etc.) at certain significance level (probability level). The outcome of such a hypothesis test helps us in determining whether or not there is a significant difference in the value of the variable under two different time spans or experimental conditions under investigation.
I am working as a police officer in southern California, therefore, I decided to perform hypothesis test on a data pertaining to crime rate. I have chosen to examine the question, whether there is any significant drop in theft cases between 2007 and 2008 in the city I work, using suitable hypothesis testing. The statistical analysis is presented in this paper.
2. Data Collection - Proposed
As I am working as a motorcycle cop it was easier for me to get data pertaining to different crimes. As this data is logged in police department as and when the cases are reported. Besides, another advantage of such a data is that no personal bias is associated while recording the data as there is no human observer of any experiment rather the data is already archived in past based on the reported cases, and while recording the data nobody was bothered if someone like me will be performing any hypothesis test on this data sometimes in future. I decided to collect data simply from the Uniform Crime Report as the variable (s) belong to my profession and also no human bias is there in the data.
Data Collection – Actual (Appendix –A and B)
I got the Uniform Crime Report data for 2007 and 2008 from my department by making an application that I need this data for statistical analysis of the same. The Uniform Crime Report for the year 2007 and 2008 is presented in the appendix. This report contains number of cases (month wise) for different crimes like theft, burglary, robbery, arson, assault, rape etc. From this data I chose to investigate the cases of theft as this was the crime reported in the maximum number.
3. Analysis of Data
I decided to analyze the month wise data on theft cases. I performed all the statistical analysis using a software package MS Office – Excel. This is a very good software package...