stats-Z-Tests & T-Tests
Question # 00012466
Posted By:
Updated on: 04/16/2014 03:42 AM Due on: 05/12/2014
1. Much has been made about the overall intelligence of criminal offenders in general, and violent
offenders in particular. There is an assumption that violent offenders are inherently less intelligent
than non-violent offenders. To test this idea, data were collected from two separate groups of
offenders (violent offenders and property offenders). Intelligence scores were obtained for every
offender in the two samples.
2. Please submit your solution (step-by-step calculations), and the conclusion here. Descriptive
Statistics appear below:
Property Offenders - Average IQ = 96, sd = 8.5, n=225
Violent Offenders - Average IQ = 88, sd = 7.5, n=200
Use t to test the following set of hypotheses at the 95% level of confidence:
Ha: Violent offenders are less intelligent than property offenders
Ho: Violent offenders and property offenders do not differ significantly with regard to intelligence scores
Homework Problems
1. It is thought that one tangible benefit of increasing the educational requirements for incoming
police officers would be a decrease in the number of police brutality complaints filed by citizens
each year. To test this idea, we can use Z to test two independent samples of police officers -one group with college degrees, the other without. A random sample of officers was selected from
one state.
2. Please submit your solution (step-by-step calculations ), and the conclusion, at the 95% level of
confidence, here. The data and hypotheses are as follows:
% of College educated officers who had an abuse
complaint filed against them in the previous 12
months
15
N=485
% of Non-college educated officers who had an ab
complaint filed against them in the previous 12 mo
18
N=612
Ha: College-educated officers will have fewer abuse complaints filed against them
Ho: Their levels of education do not affect the proportion of abuse complaints filed against police officers
offenders in particular. There is an assumption that violent offenders are inherently less intelligent
than non-violent offenders. To test this idea, data were collected from two separate groups of
offenders (violent offenders and property offenders). Intelligence scores were obtained for every
offender in the two samples.
2. Please submit your solution (step-by-step calculations), and the conclusion here. Descriptive
Statistics appear below:
Property Offenders - Average IQ = 96, sd = 8.5, n=225
Violent Offenders - Average IQ = 88, sd = 7.5, n=200
Use t to test the following set of hypotheses at the 95% level of confidence:
Ha: Violent offenders are less intelligent than property offenders
Ho: Violent offenders and property offenders do not differ significantly with regard to intelligence scores
Homework Problems
1. It is thought that one tangible benefit of increasing the educational requirements for incoming
police officers would be a decrease in the number of police brutality complaints filed by citizens
each year. To test this idea, we can use Z to test two independent samples of police officers -one group with college degrees, the other without. A random sample of officers was selected from
one state.
2. Please submit your solution (step-by-step calculations ), and the conclusion, at the 95% level of
confidence, here. The data and hypotheses are as follows:
% of College educated officers who had an abuse
complaint filed against them in the previous 12
months
15
N=485
% of Non-college educated officers who had an ab
complaint filed against them in the previous 12 mo
18
N=612
Ha: College-educated officers will have fewer abuse complaints filed against them
Ho: Their levels of education do not affect the proportion of abuse complaints filed against police officers
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Rating:
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Solution: stats-Z-Tests & T-Tests