Pearson r
Item 1
What is the correlation between these two variables:
Stress Sense of Humor
4 2
10 8
12 11
5 3
7 8
6 7
2 3
14 13
SSx = _____
SSy = _____
SSxy = _____
r = _____
Item 2
What is the correlation between these two variables:
Laughter Statistics
11 19
3 6
5 6
15 12
7 8
6 7
9 14
SSx = _____
SSy = _____
SSxy = _____
r = _____
Item 3
How much variance is accounted for between these two variables:
Strength Speed
12 3
9 7
6 9
3 11
1 15
7 6
SSx = _____
SSy = _____
SSxy = _____
r = _____
rsquared = _____
Item 4
What is the correlation between these two variables:
Strength Peace
2 2
6 5
7 8
14 19
15 12
9 8
4 5
SSx = _____
SSy = _____
SSxy = _____
r = _____
rsquared = _____
Item 5
How much variance is NOT accounted for between these two variables
Strength Anxiety
2 3
9 7
3 4
1 1
7 12
SSx = _____
SSy = _____
SSxy = _____
r = _____
r2 = _____
1 – r2 = _____
Item 6
Is there a significant relationship between the number of petals on a flower and how much the elephant plant weighs
Petals Weight
18 1
15 7
8 11
6 6
4 18
2 22
SSx = _____
SSy = _____
SSxy = _____
r = _____
r2 = _____
Item 7
What percent of variance do love and peace have in common
Love Peace
12 1
22 3
8 0
19 1
2 11
9 4
7 5
SSx = _____
SSy = _____
SSxy = _____
r = _____
r2 = _____
ANSWERS
Item 1
What is the correlation between these two variables:
Stress Sense of Humor
4 2
10 8
12 11
5 3
7 8
6 7
2 3
14 13
SSx = 120.00
SSy = 110.88
SSxy = 108.50
r = .94
Item 2
What is the correlation between these two variables:
Laughter Statistics
11 19
3 6
5 6
15 12
7 8
6 7
9 14
SSx = 98.00
SSy = 145.43
SSxy = 85.00
r = .71
Item 3
How much variance is accounted for between these two variables:
Strength Speed
12 3
9 7
6 9
3 11
1 15
7 5
SSx = 79.33
SSy = 87.50
SSxy = – 80.00
r = – .96
r2 = .92 or 92% of the mutual variance is accounted for
Item 4
What is the correlation between these two variables:
Strength Peace
2 2
6 5
7 8
14 19
15 12
9 8
4 5
SSx = 142.86
SSy = 189.71
SSxy = 147.57
r = .896
Just for practice here is the r2 = .80 or 80% of the mutual variance
Item 5
How much variance is NOT accounted for between these two variables:
Strength Anxiety
2 3
9 7
3 4
1 1
7 12
SSx = 47.20
SSy = 73.20
SSxy = 47.20
r = .80
r2 = .65 or 65%
1 – r2 = .35 or 35
Item 6
Is there a significant relationship between the number of petals on a flower and how much the elephant plant weighs:
Petals Weight
18 1
15 7
8 11
6 6
4 18
2 22
SSx = 200.83
SSy = 310.83
SSxy = – 211.17
r = – .85
r2 = .71
Check r against the Critical values of the Pearson r table using 4 degrees of freedom = .811
Since r of .85 is larger than the table r of .81, this correlation is significant and the relationship you see is not likely to be due to chance.
Item 7
What percent of variance do love and peace have in common
Love Peace
12 1
22 3
8 0
19 1
2 11
9 4
7 5
SSx = 245.43
SSy = 83.71
SSxy = – 92.14
r = – .59
r2 = 34%
