Extra Credit Assignment

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. Chi-Square and Lambda.

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) Use the table above and carry out a chi-square test manually.

            b) Calculate lambda manually. Is the relationship strong?

            c) Replicate the results above using SPSS and circle the values for significance and lamda.

            d) Using the SPSS chi square table, find out the confidence level using that this relationship is reaching.

3. Regression analysis

Dependent variable (y):
            Percent women in lower house of parliament I/R variable, raw percentages
Independent variables (x): Union density I/R variable, raw percentages
PR (proportional representation) system Yes or No, with yes = 1 and no = 0
Given the results below, please answer the following:

a.      How effective is this model? (Use adjusted R2 )

b.     Provide a substantive interpretation of the slope coefficient for Union Density.

c.      Analyze the relationship using the significance level.

 

Model Summary

Model

R

R Square

Adjusted R Square

Std. Error of the Estimate

1

.524a

.274

.252

9.03807

a. Predictors: (Constant), PR system?, 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

PR system?

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. (You can use SPSS. Make sure to include the directional hypothesis, null hypothesis, significance, strength, direction, and substantive interpretation in your discussion.  Highlight the relevant numbers.) You are not required to use a Chi-square test.

Second, add the gender variable as a control variable and find out if the original relationship remains the same.

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

2.00

10

2.00

2.00

2.00

 

Support for Gun Controls: 1 support; 2 do not support
Education Level: 1 college graduate; 2 high school graduate or lower
Gender: 1 male; 2 female