CRJ 716 – MIDTERM EXAMProf. Agron Kaci

Name: ____________Part I: Univariate Analysis

I.RECODE / FREQUENCIES Exercise Open file: 2008CrimeIndex.sav25 points

Using the 2008CrimeIndex.SAV data file create a new variable MURDER2 based on MURDER variable. The new MURDER2 variable will have the following 2 (two) categories:

Less than 1 murder per week 1 or more murders per week

Remember: The year has 52 weeks, so this number should be used to create mutually non-exclusive categories.

1. Which method (PASW procedure) did you use to create the new variable? ______ ______

2. Label the new categories/values with the above italicized labels.3. Copy and paste the log of the Recode procedure below. The log is found in the Output Window.

Please note that you may have another log description in your Output window which corresponds to the opening of the file. When you paste the entire log below, delete the first log. The second log that you should leave will start with the word/command “GET”.

Log goes here…

________________

4. Run a frequency table and a bar chart for the newly created variable-MURDER2. The bar chart should display percentages rather than frequencies. Copy and paste the table and the bar chart below:Table goes here…________________

Bar Chart goes here…________________

5. What is the percentage of states that have 1 or more murders per week? Is that higher or lower than states that have less than 1 murder in a week? (Remember: Report the valid percentages) ________________

CRJ 716 – MIDTERM EXAM Page 1 of 4

CRJ 716 – MIDTERM EXAMProf. Agron Kaci

II. COMPUTE / DESCRIPTIVE STATISTICS / Open file: prison.savFREQUENCIES / EXPLORE Exercise 25 points

In the prison.SAV data set you’ll find the number of male and female prisoners and the population for each state in the country. The trick is to create a new variable (using the above variables) that shows the prison rate of the male and female prisoners in a given state. The rate is very important since only this allows us to compare prison rates in different areas where the size of the population is different.

A) Rates, or crime rates (also referred to as the “crime index”) are based on a rate per 100,000 persons. If your county’s rate of burglaries is 98, this means that for every 100,000 people in the population, there were 98 burglaries.B) The number of 100,000 is a standard in order to get whole numbers instead of fractions of the numbers and helps us to simplify the comparison.

To create the prisoners’ rate you need to compute two (2) new variables, MALERATE and FEMRATE, using the formula: = (prisoners / population)*100000 in the COMPUTE function of PASW, where prisoners will be the “male” and “female” variables—separately. Once you create these two new variables, paste the syntax (Log) from the Output window here:

Log goes here…

____________Prepare and/or run the appropriate procedure(s) (Descriptive Statistics, Frequencies, Explore, and/or Q-Q Plots) to answer the following questions for the new variables you just created. Enter your responses in the space provided in the table below:

MaleRate FemRate

Mean vs. Median vs. Mode:

St. deviation vs. Mean

(st. deviation) (Mean)

(st. deviation) (Mean)

68% of cases fall between: and and

Are there any outliers

in the distribution?

Yes No Yes No

Overall distribution is

roughly:

Normal Somewhat normal

Not normal

Normal Somewhat normal

Not normal

CRJ 716 – MIDTERM EXAM Page 2 of 4

CRJ 716 – MIDTERM EXAMProf. Agron Kaci

Part II: Bivariate Analysis

III. CROSSTABULATION Exercise Open file: binge.sav 25 points

In part, because of rising fear about drinking and driving, all 50 states raised the age for legal purchase of alcoholic beverages to 21. Despite this legal barrier, it is widely known that many younger Americans drink before they are 21. In fact, most full-time college students are under 21.

Would you hypothesize that students who are 21 and over would engage in more binge drinking than younger students (thereby indicating the impact of the law)? – or

Would you hypothesize that students under 21 will binge more (perhaps indicating the allure of “forbidden fruit”)?

As you know, AGE is a ratio variable. As such, you need to recode it (into new variable AGECAT2) into two categories: under 21 and 21 and over. Make sure the new categories are mutually exclusive, so that 21-year olds are included only in 21 and over.

1. State the Research Hypothesis and Alternative Hypothesis:a. Research Hypothesis: ________________b. Alternative Hypothesis: ________________

2. State the Independent and Dependent variables. Only the variable name would suffice.

a. Independent variable: ________________b. Dependent variable: ________________

3. Run the crosstabulation according to the methods we have learned. Paste the table here: Table goes here…

________________

4. Which hypothesis is more accurate? ________________

a. Why? What is the epsilon value? (Mention numbers/percentages)________________

5. What is the impact of the law on binge drinking according to the table analysis? What would you answer questions stated in the paragraph above?________________

CRJ 716 – MIDTERM EXAM Page 3 of 4

CRJ 716 – MIDTERM EXAMProf. Agron Kaci

IV. Lambda and Chi-Square Exercise Open file: 2004_revised.sav 25 points

As we know, association means that two variables are related to the extent that knowing a person’s attribute on one will help you guess his or her attribute on the other. With this in mind, find and interpret Lambda and Chi-Square values regarding the relationship between gender and abortion for any reason in the gss2004_revised.sav file.

1. State the Null Hypothesis and Alternative Hypothesis:a. Null Hypothesis (Ho): ________________b. Alternative Hypothesis (Ha): ________________

2. State the Independent and Dependent variables. Only the variable name would suffice.

a. Independent variable: ________________b. Dependent variable: ________________

3. Run the crosstabulation according to the methods we have learned. Paste only the appropriate tables here (i.e.: Lambda and Chi-Square tables):

Lambda table goes here…

________________

Chi-square table goes here…

________________

4. What is the value of Lambda? What does it mean?________________

5. What is the value of Chi-Square? (Remember: you report the p-value!).________________

6. Based on the Chi-Square value, do we reject or fail to reject the Null Hypothesis at the .05 significance level? Elaborate you answer in plain English, as if you were presenting it to a non-statistician person.________________

CRJ 716 – MIDTERM EXAM Page 4 of 4