Quiz: Correlation
Due Oct 5 at 11:59pm
Points 30
Questions 10
Time Limit 45 Minutes
Allowed Attempts Unlimited
This quiz is no longer available as the course has been concluded.
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Score for this attempt: 30 out of 30
Submitted Aug 20 at 10:13am
This attempt took 24 minutes.
Question 1
3 / 3 pts
A positive correlation can be described as ________.
X decreases Y decreases
X increases Y decreases
X decreases Y increases
X increases Y varies randomly
Question 2
3 / 3 pts
All of the following problematic patterns of scatterplots can unduly influence the strength or direction of
Pearson's r except:
diagonal from lower left to upper right
curvlinear
Xoutliers
Youtliers
LATEST Attempt 1 24 minutes 30 out of 30
Question 3
3 / 3 pts
One way to look for outliers in a scatterplot is to find:
discordant pairs
concordant pairs
high correlations
low correlations
Question 4
3 / 3 pts
A researcher can calculate the correlation coefficient between two variables when the _____ is ______.
dependent variable; quantitative
dependent variable; categorical
independent variable; categorical
number of groups; is greater than two
Question 5
3 / 3 pts
An interaction effect is evidenced by:
different slopes for different
groups similar slopes for
different groups
identical slopes for different groups
slopes that are parallel to the X axis
Question 6
3 / 3 pts
A negative correlation might be described as ________.
X decreases Y decreases
X decreases Y increases
X varies randomly Y decreases
X increases Y varies randomly
Question 7
3 / 3 pts
How many pairwise correlations does SPSS permit a researcher to conduct at one time?
only limited by the number of variables in the data
one
two
fifteen
Question 8
3 / 3 pts
For which of these reasons would a researcher create a scatterplot between two variables?
To get a sense of the strength of the relationship
To calculate the degrees of freedom
To see if the variables are categorical or continuos
To see if the group means are the same
Question 9
3 / 3 pts
A policeman believes that the more text messages drivers send while driving, the greater the likelihood
of being in a car accident. Which of the following findings would support his belief?
r(30) = .38, p < .05
r(40) = -.28,
p > .05 r(30)
= -.38, p < .05
r(40) = .28, p < .01
Question 10
3 / 3 pts
Which statistic more accurately represents the percentage of variance not accounted for in the
relationship between X and Y.
(1 - r2)
z
η
r2
Quiz Score: 30 out of 30
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