22. Describe the variables. What type of scale are they measured on?
•
Variables are the two exam scores and are measure on a point scale ranging to 200
points possible for exam 1 and 400 points possible for the final exam.
23. How do you run a correlation in SPSS?
1.
Graphs
à
Legacy Dialogs
à
Scatter/Dot
2.
Click “Simple Scatter”
à
“Define”
3.
Choose variables for x and y axes and click “ok”
24. Run the correlation in SPSS. Paste in the output.
Descriptive Statistics
Mean
Std.
Deviation
N
Exam 1
164.54
22.250
28
Final Exam
331.21
56.820
28
Correlations
Exam 1
Final Exam
Exam 1
Pearson
Correlation
1
.934
**
Sig. (2
tailed)
.000
N
28
28
Final Exam Pearson
Correlation
.934
**
1
Sig. (2
tailed)
.000
N
28
28
**. Correlation is significant at the 0.01 level (2
tailed).
25. Label the pvalue on the output. What is alpha? Is the pvalue greater or less than
alpha? Did you reject or fail to reject the null hypothesis?
•
Pvalue = .05
•
.05>.001
•
We reject the null
26. Write a summary of your results using APA style.
•
We ran a correlation on the different scores in a class for exam 1 (
M
=164.54,
SD
=22.250) and students’ final exam scores (
M
=331.24,
SD
=56.82) in a sample
of college students in an intro statistics class (
n
=28) and found a significant
positive, linear correlation between exam 1 and the final exam,
r
(26) = .934,
p
= .
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View Full Document001. Thus, the higher scores on exam 1 correspond with the students who also got
a high score on the final exam.
27. What are the three possible directions of causality? Give an example of two variables
that are associated and explain their relationship in terms of the three possible directions
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 Spring '09
 Dr.Hall
 Statistics, Linear Regression, Regression Analysis, Correlation and dependence, Errors and residuals in statistics

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