Practice Problem ANSWERS: Correlation
November 3, 2008 by kltangen
Filed under Calc Solutions
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 6
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
NOW YOU CHOOSE:
Day 5: Correlation
Bit More About Correlation
Even More About Correlation
Calculate Correlation
Practice Problems
More Practice Problems
Word Problems
Sim1 Sim2 Sim3
Sim4 Sim5 Sim6
Sim7 Sim8 Sim9
Basic Facts About Correlation
Vocabulary
Formulas
Quiz 5
Summary
Practice Problem Answers: z-scores
October 22, 2008 by kltangen
Filed under Calc Solutions
Item 1
Calculate the z-score, assuming:
X = 10
mean = 50
stdev = 10
X – mean = – 40
z score = – 4.0
Item 2
Calculate the z-score, assuming:
X = 80
mean = 50
stdev = 15
X – mean = 30
z score = 2.0
Item 3
Calculate the z-score, assuming:
X = 112
mean = 100
stdev = 15
X – mean = 12
z score = .80
Item 4
Calculate the raw score, assuming:
z = 1.5
mean = 115
stdev = 10
z * stdev = 15
X = 130
Item 5
Calculate the raw score, assuming:
z = -1.37
mean = 100
stdev = 20
z * stdev = 27.4
X = 72.6
Item 6
Calculate the raw score, assuming:
z = 2.54
mean = 80
stdev = 20
X = 130.8
2.54*20 = 50.8
50.8 + 80 = 130.8
Day 4: z-Score
A Bit More About z-Scores
Even More About z-Scores
How To Calculate z-Scores
Practice Problems
Basic Facts About z-Scores
Vocabulary
Formulas For z-Scores
Quiz 4
Summary
More Practice Problems ANSWERS: Dispersion
October 22, 2008 by kltangen
Filed under Calc Solutions
Item 6
Calculate the SS of the following scores:
2
2
2
5
5
5
7
SS = 24
Item 7
Calculate the range and SS of the following scores:
2
5
7
3
3
13
19
4
range = 17
SS = 250
Item 8
Calculate the SS and stdev of the following population scores:
11
10
12
2
4
7
SS = 81.33
variance = 13.56
Item 9
Calculate the stdev. of the following population:
14
3
5
8
6
9
SumX = 45
SS = 73.50
variance = 12.25
stdev. = 3.50
Item 10
Calculate the SS of the following sample:
5
7
7
6
3
2
SS = 22.00
NOW YOU CHOOSE:
Day 3: Dispersion
A Bit More About Dispersion
Even More About Dispersion
Range
MAD
Sum of Squares
Variance
Standard Deviation
How To Calculate
Range
MAD
Sum of Squares
Variance
Standard Deviation
Formulas For Dispersion
Practice Problems
More Practice Problems
Basic Facts About Dispersion
Vocabulary
Quiz 3
Summary
