PSYCH/625 Version 1 Time to Practice � Week Five University of Phoenix Material
Week five material for a psychology course.
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Time to Practice – Week Five
PSYCH/625 Version 1
1
Copyright © 2013 by University of Phoenix. All rights reserved.
PSYCH/625 Version 1 Time to Practice – Week Five
University of Phoenix Material
Time to Practice – Week Five
Complete Parts A, B, and C below.
Part A
Some questions in Part A require that you access data from Statistics for People Who (Think They) Hate
Statistics. This data is available on the student website under the Student Text Resources link.
1. Use the following data to answer Questions 1a and 1b.
Total no. of problems
correct (out of a possible
20)
Attitude toward test taking
(out of a possible 100)
17 94
13 73
12 59
15 80
16 93
14 85
16 66
16 79
18 77
19 91
a. Compute the Pearson product-moment correlation coefficient by hand and show all your work.
Considering, x = total number of correct problems and y = Attitude, we have,
𝑛 = 10, 𝑥̅ = 15.6, 𝑦ത = 79.7, 𝑥𝑦 = 12568, 𝑥2 = 2476 𝑎𝑛𝑑 𝑦2 = 64727
Thus,
Correlation coefficient = ∑ 𝑥𝑦−𝑛𝑥̅ 𝑦ത
ඥ(∑ 𝑥2−𝑛𝑥̅ 2)(∑ 𝑦2−𝑛𝑦2) = 0.5961
b. Construct a scatterplot for these 10 values by hand. Based on the scatterplot, would you predict
the correlation to be direct or indirect? Why?
The scatter plot is given below.
PSYCH/625 Version 1
1
Copyright © 2013 by University of Phoenix. All rights reserved.
PSYCH/625 Version 1 Time to Practice – Week Five
University of Phoenix Material
Time to Practice – Week Five
Complete Parts A, B, and C below.
Part A
Some questions in Part A require that you access data from Statistics for People Who (Think They) Hate
Statistics. This data is available on the student website under the Student Text Resources link.
1. Use the following data to answer Questions 1a and 1b.
Total no. of problems
correct (out of a possible
20)
Attitude toward test taking
(out of a possible 100)
17 94
13 73
12 59
15 80
16 93
14 85
16 66
16 79
18 77
19 91
a. Compute the Pearson product-moment correlation coefficient by hand and show all your work.
Considering, x = total number of correct problems and y = Attitude, we have,
𝑛 = 10, 𝑥̅ = 15.6, 𝑦ത = 79.7, 𝑥𝑦 = 12568, 𝑥2 = 2476 𝑎𝑛𝑑 𝑦2 = 64727
Thus,
Correlation coefficient = ∑ 𝑥𝑦−𝑛𝑥̅ 𝑦ത
ඥ(∑ 𝑥2−𝑛𝑥̅ 2)(∑ 𝑦2−𝑛𝑦2) = 0.5961
b. Construct a scatterplot for these 10 values by hand. Based on the scatterplot, would you predict
the correlation to be direct or indirect? Why?
The scatter plot is given below.
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Document Details
University
University of Phoenix
Subject
Psychology