EDUC 606-LEARNING ACTIVITY 3

EDUC 606

LEARNING ACTIVITY 3 INSTRUCTIONS
This learning activity consists of a variety of problems from Chapters 13–15. Include a title page
with your assignment in current APA format. Spaces for answers are provided. Submit your
assignment as a Word document.
1. (20 Pts, 1 Pt each). Calculate the mean, median, mode, standard deviation, and range for
the following sets of measurements (fill out the table):
a. 9, 7, 6, 6, 2
b. 12, 10, 9, 8, 6
c. 82, 82, 82, 82, 82
d. 12, 10, 9, 8, 6, 45
DISTRIB
a.
b.
c.
d.

MEAN

MEDIAN

MODE

SD

RANGE

2. (20 Pts, 5 pts each) Answer the following questions:
a. Why is the SD in (d) so large compared to the SD in (b)?

b. Why is the mean so much higher in (d) than in (b)?

c. Why is the median relatively unaffected?

d. Which measure of central tendency best represents the set of scores in (d)? Why?

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EDUC 606

3. (24 pts, 2 pts each) Fill in the blanks on the table with the appropriate raw scores, zscores, T-scores, and approximate percentile ranks. You may refer to the distribution
curve below.
Note: the Mean = 50, SD = 5.

RAW
35

z

T

Percentile

1.2
35
16

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EDUC 606

4. (20 pts, 2 pts each) The Graduate Record Exam (GRE) has a combined verbal and
quantitative mean of 1000 and a standard deviation of 200. Scores range from 200 to
1600 and are approximately normally distributed. For each of the following problems:
(a) Indicate the percentage or score called for by the problem.
(b) Select the appropriate distribution curve (from below) that relates to the problem.

a. What percentage of the persons who take the test score above 1300? _______
Select the curve best representing your answer: _______
b. What percentage of the persons who take the test score above 800? _______
Select the curve best representing your answer: _______
c. What percentage of the persons who take the test score below 1200? _______
Select the curve best representing your answer: _______
d. Above what score do the top 20% of the test-takers score? _______
Select the curve best representing your answer: _______
e. Below what score do the bottom 16% of the test-takers score? _______
Select the curve best representing your answer: _______

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EDUC 606

5. (16 pts, varied) Refer to the following data and scatterplots to respond to questions 5a–5f.
Individual
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16

Score on political
awareness test
24
16
11
9
8
14
17
19
21
25
18
13
11
6
9
12

Score on current
events test
23
12
11
6
13
11
16
16
21
25
11
13
14
10
10
7

Figure A represents a scatterplot constructed from the data; Figure B represents a
regression line drawn through the scatterplot that “fits” the data points reasonably well;
Figure C represents an ellipse drawn around the data points
a.

(2 pts.) Estimate the direction of the correlation: ________________________

b.

(2 pts.) Estimate the strength of the correlation coefficient: __________________

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EDUC 606

c.

(2 pts.) Consider Figure D (below), and use only the data points associated with
current event scores of 15 and lower; what effects does this have on the direction
and strength of the correlation coefficient?

d.

(4 pts.) Explain why this is the case.

e.

(2 pts.) Explain in words what a non-truncated scatterplot means.

f.

(4 pts.) Identify how likely it is that a causal relationship has been indicated.

Learning Activity 3 is due by 11:59 p.m. (ET) on Sunday of Module/Week 5.

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