Extra Credit Assignment

*Show your work. Make sure to include output tables. Do not include irrelevant tables.

1.         Z-score

            Assume a normal distribution with a mean of 40 and a standard deviation of 6 and answer the following questions.

             a.         Find the proportion of the area beyond 50 (i.e. above 50).

-- Draw a normal curve and place the mean and the score 50.

-- Shade the area beyond 50.

-- Translate the score 50 to a z score using the z formula.

-- Find the proportion of the shaded area.

             b.         Find the proportion of the area between 50 and the mean.

             c.         Find the proportion of the area below the score of 50.

             d.         Find the proportion of the area below the score of 40.

             e.         Find the proportion of the area between the scores of 50 and 30.

 

2.         Analyze the relationship between the two variables below:

Political ID

Republican = 1

Democrat = 2

Income

Low = 1

High = 2

1

2

1

2

2

1

2

1

1

2

2

2

2

2

2

1

2

1

1

2

1

1

2

2

1

1

1

1

 

    a) State the null and directional hypotheses.

    b) Carry out a test of statistical significance manually and compute a measure of association

    c) Reproduce the results above using SPSS. Circle the significance and discuss the confidence level. Also, circle the statistic for the measure of association and discuss the strength.

    d) Is the directional hypothesis supported?

3.   Using the output tables below, analyze the impact of Union Density on % Women in Lower House. Make sure to discuss the significance level, slope coefficient, adjusted R2 and whether or not a directional hypothesis is supported.            

Model Summary

Model

R

R Square

Adjusted R Square

Std. Error of the Estimate

1

.524a

.274

.252

9.03807

a. Predictors: (Constant), Proportional representation?, Union density(%)

                       

Coefficientsa

Model

Unstandardized Coefficients

Standardized Coefficients

t

Sig.

B

Std. Error

Beta

1

(Constant)

9.083

2.175

 

4.177

.000

Union density (%)

.213

.063

.371

3.407

.001

Proportional representation

6.164

2.292

.292

2.689

.009

a. Dependent Variable: Percent women in lower house of parliament, 2005

 

 

4.         First, analyze the relationship between support for gun controls and education level. Second, add the gender variable as a control variable and find out if the original relationship remains the same.

(Use SPSS. Make sure to include the directional hypothesis, null hypothesis, significance, strength, direction, and substantive interpretation in your discussion.)

 

ID

Support for Gun controls

 

Education Level

Gender

1

1.00

1.00

2.00

2

1.00

1.00

2.00

3

1.00

1.00

1.00

4

1.00

1.00

2.00

5

1.00

1.00

1.00

6

2.00

2.00

1.00

7

1.00

1.00

1.00

8

1.00

2.00

1.00

9

2.00

2.00

1.00

10

2.00

2.00

1.00

 

Support for Gun Controls: 1 – support; 2 – doesn’t support , Education Level:  1 – college graduate; 2 – high school graduate, Gender: 1 – male; 2 – female

5. Analyze the impact of education and negative ads on turnout using the data below:

City Turnout Years of schooling %Negative ads
A 55 11.9 60
B 60 12.1 63
C 65 12.7 55
D 68 12.8 53
E 70 13.0 48

    a) State the null and directional hypotheses for each independent variable.

    b) Manually calculate a measure of association for each relationship separately (i.e. bivariate analysis) and carry out a test of significance.

    c) Manually calculate the intercept and the slope coefficients for each relationship separately.

    d) Reproduce the results above for each relationship separately using SPSS and interpret the results. Make sure to include the following in your discussion: significance, confidence level, substantive interpretation of the slope coefficient, adj R sqd.  

    e) Using SPSS, carry out multiple regression by including both independent variables in the model and interpret the results.