Question 1
5 out of 5 points
When a correlation exists, lowering the range of either of the variables will _________.
Question 2
5 out of 5 points
In a negative relationship, _________.
Question 3
5 out of 5 points
If one calculates r for raw scores, and then calculates r on the z scores of the same data, the value of r will _______.
Question 4
5 out of 5 points
If one takes a sample of pairs of points over a narrow range of X or Y scores, what effect might this have on the value of r?
Question 5
5 out of 5 points
In the equation Y = bX + a, X and Y, a is _________.
Question 6
0 out of 5 points
You have conducted a brilliant study which correlates IQ score with income and find a value of r = 0.75. At the end of the study you find out all the IQ scores were scored 10 points too high. What will the value of r be with the corrected data?
Question 7
5 out of 5 points
Correlation and regression differ in that _________.
Question 8
5 out of 5 points
A traffic safety officer conducted an experiment to determine whether there is a correlation between people’s ages and driving speeds. Six individuals were randomly sampled and the following data were collected.
Age
20
25
45
46
60
65
Speed (mph)
60
47
55
38
45
35
The value of Pearson r equals _________.
Question 9
5 out of 5 points
In a perfect relationship, _________.
Question 10
5 out of 5 points
A relationship can be _________.
Question 11
5 out of 5 points
If N is small, an extreme score _________.
Question 12
5 out of 5 points
In an imperfect relationship, _________.
Question 13
5 out of 5 points
If the correlation between variables X and Y is 0.95, which of the following is true?
Question 14
5 out of 5 points
For the following X and Y scores, how much of the variability of Y is accounted for by knowledge of X? Assume a linear relationship.
X
20
15
6
10
Y
6
5
4
0
Question 15
5 out of 5 points
Which Pearson correlation coefficient shows the strongest relationship between two variables?
Question 16
5 out of 5 points
Correlation implies causation.
Question 17
5 out of 5 points
In a positive relationship, _________.
Question 18
5 out of 5 points
After several studies, Professor Smith concludes that there is a zero correlation between body weight and bad tempers. This means that _________.
Question 19
5 out of 5 points
It is possible to compute a coefficient of correlation if one is given _________.
Question 20
5 out of 5 points
If two variables are ratio scaled and the relationship is linear, what type of correlation coefficient is most appropriate?
