1. A researcher is planning to evaluate the effect of body-worn cameras on arrest decisions among officers. The study will assess how body-worn cameras change the total count of arrests an officer makes each week. Specifically, the researcher wants to see the effect of body-worn cameras on these types of officers: male and female officers, officers who are on night shifts versus day shifts, officers with a college degree and without a college degree, and officers working in urban neighborhoods versus rural neighborhoods.

(1) How many subgroups of officers this study will have?

(2) Write out these subgroups.

(3) Suppose the researcher will invite 6 officers for each subgroup (based on voluntariness). In total, how many officers will be in this experiment?

(4) The research team plans to give a 50-dollar Amazon gift card as an incentive to each participant. Based on the total number of officers you identified in (3), determine the total cost of Amazon gift cards.

2. Use the data set "SPSS data-prisoner" and SPSS to solve these questions. The "label" column in the data shows the meaning of each variable. Click this to download the data set: SPSS data-prisoner.savDownload SPSS data-prisoner.sav

(1) Focus on the variable "cokage0," meaning "age first used cocaine (not injected)." If you want to conduct a t test to examine whether males and females have the same starting age of cocaine use. Which type of t test you will use?

(2) If you want to conduct a t test to examine whether males and females have the same starting age of cocaine use, what is your hypothesis for the t test?

(3) Use SPSS to conduct the t test in (1). Paste the screenshot of the results and use your results and determine whether you reject your hypothesis. Explain why.

(4) Use SPSS to obtain the average starting age of arrest of all the people in this data. Paste screenshots and write out your responses.

(5) Use SPSS to obtain a histogram of the variable in (4). Do you observe a lump? In what age range you see people are clustered? Paste screenshots and write out your responses.

(6) Use SPSS to obtain the average starting age of arrest of males and females separately in this data. Which group has the later onset of arrest? Paste screenshots and write out your responses.

(7) Focus on the two histograms you obtained in (6). Identify the age around which you see most males experience the first arrest in life. Identify the age around which you see most females experience their first arrest in life. Paste screenshots and write out your responses.

3. Use the data set "sentencing22" and SPSS. The "label" column in the data shows the meaning of each variable. Click this to download the data set: sentencing22.savDownload sentencing22.sav

(1) Find a type of offense in which there is a higher percentage of males who committed it. Use SPSS to provide the percentages of males and females who engaged in this offense. Paste screenshots and write out your responses

(2) Use SPSS to conduct a chi-square test to determine whether the gap you observed in (1) is statistically significant. Provide your hypothesis, a screenshot of chi-square test results, and your conclusion.

(3) Find a type of offense in which there is a higher percentage of females who committed it. Use SPSS to provide the percentages of males and females who engaged in this offense. Paste screenshots and write out your responses.

(4) Use SPSS to conduct a chi-square test to determine whether the gap you observed in (3) is statistically significant. Provide your hypothesis, screenshots of chi-square test results, and your conclusion.