Week 12 - Assignments Statistics Question 5 For this problem, we have used the same X and Y values that

Week 12 - Assignments

Statistics

Question 5

For this problem, we have used the same X and Y values that appeared in problem 4, but we have changed the X, Y pairings:

X Y

1 6

2 8

4 2

5 0

3 4

Sketch a graph showing these reorganized data.
Estimate the Pearson correlation just by looking at your graph.
Compute the Pearson correlation. (Note: Much of the calculation for this problem was done already in problem 4.)

Question 10

It is well known that similarity in attitudes, beliefs, and interests plays an important role in interpersonal attraction (see Byrne, 1971, for example). Thus, correlations for attitudes between married couples should be strong. Suppose a researcher developed a questionnaire that measures how liberal or conservative one’s attitudes are. Low scores indicate that the person has liberal attitudes, whereas high scores indicate conservatism. The following hypothetical data are scores for married couples.

Couple Wife Husband

A 11 14

B 6 7

C 18 15

D 4 7

E 1 3

F 10 9

G 5 9

H 3 3

Compute the Pearson correlation for these data, and determine whether or not there is a significant correlation between attitudes for husbands and wives. Set alpha at .05, two tails.

Question 11

Correlation studies are often used to help determine whether certain characteristics are controlled more by genetic influences or by environmental influences. These studies often examine adopted children and compare their behaviors with the behaviors of their birth parents and their adoptive parents. One study examined how much time individuals spend watching TV (Plomin, Corley, DeFries, and Fulker, 1990). The following data are similar to the results obtained in the study.

Amount of time spent watching TV

Adopted Children Birth Parents Adoptive Parents

2 0 1

3 3 4

6 4 2

1 1 0

3 1 0

0 2 3

5 3 2

2 1 3

5 3 3

Compute the correlation between the children and their birth parents.
Compute the correlation between the children and their adoptive parents.
Based on the two correlations, does TV watching appear to be inherited from the birth parents or is it learned from the adoptive parents?

Question 14

A psychologist would like to determine whether there is any consistent relationship between intelligence and creativity. A random sample of n = 18 people is obtained, and the psychologist administers a standardized IQ test and a creativity test to each individual. Using these data, the psychologist obtains a Pearson correlation of r = +0.20 between IQ and creativity.

Do the sample data provide sufficient evidence to conclude that a real (nonzero) correlation exists in the population? Test at the .05 level of significance.
If the same correlation, r = 0.20, was obtained for a sample of n = 102 people, what decision would be made about the population correlation?

SPSS Assignment 1

Enter the data for Chapter 15, question 7 into SPSS.
State the null and alternative hypotheses.
Conduct a correlation test (Pearson r) at the .05 level.
Copy or copy object and paste relevant output from the statistical test.
State whether or not the null hypothesis is accepted or rejected based on the results of the statistical test. Use the conventions described by Gravetter and Wallnau on page 428 to present your report.
In a short paragraph, discuss what the results of correlation test mean regarding the relationship between anxiety level and test performance.

Question 7

To measure the relationship between anxiety level and test performance, a psychologist obtains a sample of n = 6 college students from an introductory statistics course. The students are asked to come to the laboratory 15 minutes before the final exam. In the lab, the psychologist records physiological measures of anxiety (heart rate, skin resistance, blood pressure, etc.) for each participant. In addition, the psychologist obtains the exam score for each participant. Compute the Pearson correlation for the following data:

Student Anxiety Rating Exam Score

A 5 80

B 2 88

C 7 80

D 7 79

E 4 86

F 5 85

SPSS Assignment 2

Review the layoutreadme.rtf file (provided under Doc Sharing ), which is a codebook for a quantitative study. The frss79spec.sav file (also provided under Doc Sharing ), which opens in SPSS, is the companion data file to the codebook. Examine the two files in conjunction with each other, paying attention to how the information in the codebook translates to the data file.
Submit the following:
- Answer the question: What purpose does the codebook serve?
- Using the layoutreadme.rtf file as a model, produce and submit a similar codebook for the survey you designed in Week 8.
- Generate and enter into SPSS data for at least 15 respondents to the survey you designed in Week 8. Just make up and enter the responses into SPSS for a sample of at least 15. You may enter data for more respondents if you wish to approach the sample size you have estimated for this survey study. Submit the SPSS data file.