Practice Homework -- Identify Dependent and Independent Variables, the data types, the statistical procedure, the theory and the Null Hypothesis

Homework – Problems

From the list below, identify the data-type combination and choose the correct procedure based on the study design.

a.  Pearson r,  Bivariate regression, One-Sample t-test,  Independent sample t-test,

Paired-sample t-test, One-way Chi-Square, Two-Way Chi-square

Example:  Is there a difference in the dependent variable mean “number of victimizations” among inmates between violent offenders and non-violent offenders?

 Dependent Variable     Independent Variable            Statistical Procedure

  Metric                           Nominal                     Independent Samples t-test

1.  In a study of inmates, does the mean arrests effect the dependent variable mean sentence length?

 Dependent Variable       Independent Variable                 Statistical Procedure

        ____________                    ____________                      __________________

2.  Is there a difference in the dependent variable “GRE scores” between Criminal Justice students at UNG compared to the population of Criminal Justice students nationwide?

 Dependent Variable       Independent Variable                 Statistical Procedure

        ____________                    ____________                      __________________

3.  Is the dependent variable “count of students” higher among traditional or non-traditional Criminal Justice students?

   Dependent Variable       Independent Variable                 Statistical Procedure

        ____________                    ____________                      __________________

 4.  Is there a difference in the dependent variable “mean number of arrests” between Hispanics and African Americans?

  Dependent Variable       Independent Variable                 Statistical Procedure

        ____________                    ____________                      __________________

 5.  Will the dependent variable “mean number of illegal immigrants” after a border tightening policy be less than before the policy was in effect?

  Dependent Variable       Independent Variable                 Statistical Procedure

        ____________                    ____________                      __________________

6.  Is there a difference in the dependent variable “count in political party affiliation” (republican or democrat) between males and females?

  Dependent Variable       Independent Variable                 Statistical Procedure

        ____________                    ____________                      __________________

7.  What “LSAT score” (dependent variable) is a Law student who has an IQ of 156 predicted to attain?

 Dependent Variable       Independent Variable                 Statistical Procedure

        ____________                    ____________                      __________________

8.  Is there a difference in the dependent variable mean “Minnesota Multi-Phasic Personality Inventory (MMPI)” score between military and civilians?

  Dependent Variable       Independent Variable                 Statistical Procedure

        ____________                    ____________                      __________________

Answers

1.  In a study of inmates, does the mean arrests effect the dependent variable mean sentence length?

  Dependent Variable       Independent Variable                Statistical Procedure

   Metric                                          Metric                                  _Pearson r_

 2.  Is there a difference in the dependent variable “GRE scores” between Criminal Justice students at UNG compared to the population of Criminal Justice students nationwide?

    Dependent Variable       Independent Variable                    Statistical Procedure

          Metric                           Nominal  (sample/population)       _One-Sample t-test_

3.  Is the dependent variable “count of students” higher among traditional or non-traditional Criminal Justice students?

   Dependent Variable       Independent Variable                     Statistical Procedure

        Count                                  Nominal                           _One-way Chi-square_

4.  Is there a difference in the dependent variable “mean number of arrests” between Hispanics and  African Americans?

Dependent Variable       Independent Variable               Statistical Procedure

          Metric                               Nominal                            Independent Sample t-test

5.  Will the dependent variable “mean number of illegal immigrants” after a border tightening policy be less than before the policy was in effect?

  Dependent Variable              Independent Variable               Statistical Procedure

             Metric                      Nominal (Before and After)       _Paired-Sample t-test_     

6.  Is there a difference in the dependent variable “count in political party affiliation” (republican or democrat) between males and females?

    Dependent Variable       Independent Variable               Statistical Procedure

        Nominal                                Nominal                            Two-Way Chi-Square_

7.  What “LSAT score” (dependent variable) is a Law student who has an IQ of 156 predicted to attain?

  Dependent Variable       Independent Variable               Statistical Procedure

         Metric                            Metric                                  Bivariate Regression

8.  Is there a difference in the dependent variable mean “Minnesota Multi-Phasic Personality Inventory (MMPI)” score between military and civilians?

 Dependent Variable       Independent Variable               Statistical Procedure

            Metric                               Nominal                        _Independent-Sample t-test_

The Null Hypothesis for differing Data-type combinations

 (The first two are already answered)

1.  The effect of additional police on number of crimes

Answer:     There is not a statistically significant relationship between number of crimes (dep) and number of police (Ind)

2.  Is there a difference in average (mean) number of victimizations between violent offenders and non-violent offenders?

Answer:  There is not a statistically significant difference in average victimizations (dep) between violent offenders and non-violent offenders (cat 1 and cat 2 ind) 

3.  In a study of inmates, do additional prior arrests affect the sentence length?

4. Is there a difference in average (mean) scores on the GRE test between a sample of Criminal Justice students at NG compared to the population of Criminal Justice students nationwide?

5. Is the “count of students” in a single variable higher among two categories: traditional or non-traditional Criminal Justice students?

6. Will the “average (mean) number of illegal immigrants” after a border tightening policy be less than before the policy was in effect?

7. Is there a difference in the count of persons belonging to political "party affiliation” (republican or democrat) between males and females?

8. What is the predicted LSAT score of a law-school student who scores 156 on the IQ test?

9. Is there a difference in average (mean) scores on the Minnesota Multi-Phasic Personality Inventory (MMPI test) between military and civilians?

10. Is there is a difference in average (mean) income between different ethnic groups: white and nonwhite police officers.

11. A researcher conducted a study on job satisfaction between two employers:  Federal employees and city/state employees.  He has heard that federal jobs are more desirable, so he devised a job-satisfaction scale from 1 to 10, (1 = very dissatisfied, 10 = very satisfied), to ascertain if employer type made a difference in job satisfaction.

12. Who has more average (mean) repeat offenses, inmates under age-40 or inmates age-40 and over?

13. A social worker theorizes that higher levels of parental education lessens the frequency of the child’s delinquency.  

14. It is commonly theorized that liberals donate more money on average (mean) to charity than do conservatives.

15. A social scientist believes that, because married adults have the potential for two incomes, they will have more average (mean) disposable income than single adults.

16. A political scientist is asked to research landslide winners in political contests (Governors were surveyed). The goal is to discover if “popularity in elections” is related to job effectiveness. He gathers data on how many “votes” were received by both candidates in the 50 state elections over the past 3 years, and how many “executive actions” the winner took while in office. 

17. Is happiness in marriage related to income level? A researcher asked 40 subjects to rate their “marriage happiness” (rated on a scale of 1 to 6, 1 being near divorce and 6 being blissful), and the couple’s yearly income.

18. A CJ major is trying to find out if the crime rate is higher in areas with one or two officer patrols. It is theorized that the average (mean) “crime,” is higher in one-officer “patrols.” She collects data from 35 districts.

19. Certain special interest groups have convinced many voters through a media campaign that ethnic minority couples typically have more children on average (mean)  than Caucasian couples.

20. A Researcher wants to determine the relationship between hours spent viewing video streams and education.

21. A drug identification unit wants to determine the “reaction time in seconds” between amphetamine users and those on placebos.

22. Child misbehavior (did or did not) was studied between working mothers and stay-at-home mothers

23. A follow-up study was conducted to ascertain the difference in average (mean) “GPA” between children that grew up at daycare facilities and those that grew up at home.

24. A study was conducted to test the theory that high levels of “crime” are associated with low levels of “income.” 

25. A study was conducted to test the theory that high levels of “crime” are associated with low levels of “income.”

                                                                     Answers

1.  The effect of additional police on number of crimes

 There is not a statistically significant relationship between number of crimes (dep) and number of police (Ind)

2.  Is there a difference in average (mean) number of victimizations between violent offenders and non-violent offenders?

There is not a statistically significant difference in average victimizations (dep) between violent offenders and non-violent offenders (cat 1 and cat 2  ind) 

3.  In a study of inmates, do additional prior arrests affect the sentence length

There is not a statistically significant relationship between sentence length and (dep) and prior arrests (Ind)

4. Is there a difference in average (mean) scores on the GRE test between a sample of Criminal Justice students at NG compared to the population of Criminal Justice students nationwide? 

There is not a statistically significant difference in scores on the GRE test (dep) between sample of Criminal Justice students at NG compared to the population of Criminal Justice students nationwide (cat 1 and cat 2  ind)

5. Is the “count of students” in a single variable higher among two categories: traditional or non-traditional Criminal Justice students? 

There is not a statistically significant difference in count (dep) of traditional students, among traditional or non-traditional Criminal Justice students (cat 1 and cat 2 ind), between the observed and expected count.

6. Will the “average (mean) number of illegal immigrants” after a border tightening policy be less than before the policy was in effect?

There is not a statistically significant difference in average (mean) number of illegal immigrants (dep) between before and after a border tightening policy  (cat 1 and cat 2  ind)

7. Is there a difference in the count of persons belonging to political "party affiliation” (republican or democrat) between males and females?

There is not a statistically significant difference in count (dep) of Republicans, traditional students, among males and females, (cat 1 cat 2 ind) between the observed and expected count.

8. What is the predicted LSAT score of a law-school student who scores 156 on the IQ test?

There is not a statistically significant relationship between LSAT scores (dep) and IQ scores (Ind)

9. Is there a difference in average (mean) scores on the Minnesota Multi-Phasic Personality Inventory (MMPI test) between military and civilians?

There is not a statistically significant difference in average MMPI scores (dep) between nilitary and civilian personnel (cat 1 and cat 2  ind) 

10. Is there is a difference in average (mean) income between different ethnic groups: white and nonwhite police officers.

There is not a statistically significant difference in mean income (dep) between white and nonwhite police officers (cat 1 and cat 2  ind) 

11. A researcher conducted a study on job satisfaction between two employers:  Federal employees and city/state employees.  He has heard that federal jobs are more desirable, so he devised a job-satisfaction scale from 1 to 10, (1 = very dissatisfied, 10 = very satisfied), to ascertain if employer type made a difference in job satisfaction.

There is not a statistically significant difference in job-satisfaction (dep) between Federal employees and city/state employees (cat 1 and cat 2  ind) 

12. Who has more average (mean) repeat offenses, inmates under age-40 or inmates age-40 and over?

There is not a statistically significant difference in repeat offenses (dep) between Inmates under age-40 or inmates age-40 and over (cat 1 and cat 2  ind)

13. A social worker theorizes that higher levels of parental education lessens the frequency of the child’s delinquency.

There is not a statistically significant relationship between Delinquency incidents (dep) and parental education (Ind) 

14. It is commonly theorized that liberals donate more money on average (mean) to charity than do conservatives.

There is not a statistically significant difference in money donated (dep) between Liberals and Conservatives (cat 1 and cat 2  ind)

15. A social scientist believes that, because married adults have the potential for two incomes, they will have more average (mean) disposable income than single adults.

There is not a statistically significant difference in disposable income (dep) between maried and single adults (cat 1 and cat 2  ind)

16. A political scientist is asked to research landslide winners in political contests (Governors were surveyed). The goal is to discover if “popularity in elections” is related to job effectiveness. He gathers data on how many “votes” were received by both candidates in the 50 state elections over the past 3 years, and how many “executive actions” the winner took while in office.

There is not a statistically significant relationship between number of votes (dep) and number of exectutive actions (Ind) 

17. Is happiness in marriage related to income level? A researcher asked 40 subjects to rate their “marriage happiness” (rated on a scale of 1 to 6, 1 being near divorce and 6 being blissful), and the couple’s yearly income.

There is not a statistically significant relationship between marriage happiness (dep) and income (Ind) 

18. A CJ major is trying to find out if the crime rate is higher in areas with one or two officer patrols. It is theorized that the average (mean) “crime rate,” is higher in one-officer “patrols.” She collects data from 35 districts.

There is not a statistically significant difference in crime rate (dep) between one or two officer patrols (cat 1 and cat 2  ind)

19. Certain special interest groups have convinced many voters through a media campaign that ethnic minority couples typically have more children on average (mean)  than Caucasian couples.

There is not a statistically significant difference in mean number of children (dep) between ethnic minority and Caucasian couples (cat 1 and cat 2  ind)

20. A Researcher wants to determine the relationship between hours spent viewing video streams and education.

There is not a statistically significant relationship between viewing video streams (dep) and education (Ind)

21.  A drug identification unit wants to determine the “reaction time in seconds” between before using amphetamines and after.

There is not a statistically significant difference in reaction time (dep) between before using amphetimines and after using amphetamines (cat 1 and cat 2  ind)

22. Child misbehavior (did or did not) was studied between working mothers and stay-at-home mothers

There is not a statistically significant difference in count of children who misbehavied (cat 1 dep) among working moms and stay-at-home moms (cat 1 and cat 2  ind), between the observed and expected count

23. A follow-up study was conducted to ascertain the difference in average (mean) “GPA” between children that grew up at daycare facilities and those that grew up at home.

There is not a statistically significant difference in mean child's GPA (dep), between working moms and stay-at-home moms (cat 1 and cat 2 ind)

24. A study was conducted to test the theory that high levels of “crime” are associated with low levels of “income.” 

There is not a statistically significant relationship between crime (dep) and income (Ind)

25. A study was conducted to test the theory that high levels of “burglaries” are associated with low levels of liquor consumption.

There is not a statistically significant relationship between burglaries (dep) and devil juice (Ind)