Description

Statistics Exercise V: Correlation and Regression

These weekly exercises provide the opportunity for you to understand and apply statistical methods and analysis. Unless otherwise stated, use 5% (.05) as your alpha level (cutoff for statistical significance).


#1.  What information does a correlation coefficient convey?
 
#2.  State whether each of the following is an example of a positive correlation or a negative correlation.

1. Higher education level is associated with a larger annual income.
2. Increased testosterone is associated with increased aggression.
3. The smaller the class size, the more students believe they are receiving a quality education.
4. Rising prices of apples are associated with the sale of fewer apples.

#3.  Which is the predictor variable (X) and which is the criterion variable (Y) for each of the following examples?

1. A researcher tests whether the size of an audience can predict the number of mistakes a student makes during a classroom presentation.
2. A military officer tests whether the duration of an overseas tour can predict the morale among troops overseas.
3. A social psychologist tests whether the size of a toy in cereal boxes can predict preferences for that cereal.

Use SPSS and the data file found in syllabus resources (DATA540.SAV) to answer the following questions.  Round your answers to the nearest dollar, percentage point, or whole number.  
 
#4.  What is the regression equation that would best predict relationship happiness (HAPPY) from the Lifestyle (L) score?
 
a.  HAPPY = L - .143 
b.  HAPPY = .23L – 4.5 
c.  HAPPY = .42L + .23 
d.  HAPPY = 4.47 - .018L
 
#5.  The Lifestyle score (L) measures the degree to which a participant desires a luxurious lifestyle.  The Dependency score (D) measures the degree to which a participant expects others to provide financial support.  Compute the correlation between these two variables.  Which of the statements below best describes the relationship?
 
a.  People who want a more frugal lifestyle tend to be more financially dependent. 
b.  People who want a more luxurious lifestyle tend to be more financially dependent. 
c.  People who want a more luxurious lifestyle tend to be less financially dependent. 
d.  There is no relationship between desired lifestyle and financial dependency.
 
#6.  What is the Pearson r correlation between participants’ ages and the age of their partners (AGE1, AGE2)?
a.  .000 
b.  .413 
c.  .622 
d.  .822
 
#7.  Look at the correlation between Risk-Taking (R) and Relationship Happiness (HAPPY).  Use the standard alpha level of 5%.  How would you describe the relationship?
 
a.  The relationship is non-significant. 
b.  There is a significant negative relationship. 
c.  There is a significant positive relationship. 
d.  The correlation is zero.
 
#8.  If you randomly chose someone from this sample, what is the chance that they described their relationship as either Happy or Very Happy?
 
a.  32% 
b.  37% 
c.  56% 
d.  69%