Name_______________ 1. A school teacher believes that her kindergarten students have higher IQ than average children of that age. She decided to test her hypothesis. The IQ for her class (N=30) was 106, while the population mean () is 100. The standard deviation for her class was 10. 1.1. State the null and research hypothesis ( & ) (1 POINT) 1.2. Write the statistical conclusion, assuming alpha = .05 (Show your calculations). (1 POINT) 1.3. Based on your decision to reject or fail to reject , what type of error can you be making? (Choose one) (1 POINT) Type I error Type II error 2. A high school teacher correlated the math test scores and scores on a motivation scale for her 9th graders. She was delighted to find a high correlation between the two sets of scores. Later in the semester she correlated the math test scores of mathematically gifted students who had math scores above 85th percentile and their motivation scores. She found a much lower correlation. What could be the reason for the low correlation? (1 POINT) 3. Suppose that a performance test of manual dexterity has been administered to three groups of subjects in different occupations. The data appear in the table below. Answer the following questions. Group1 Group2 Group3 22 23 27 25 26 24 27 28 23 28 22 23 23 27 27 25 26 26 24 23 22 24 27 28 25 27 25 26 25 23 25 23 23 24 28 26 26 27 25 25 25 27 26 27 27 25 27 26 25 28 25 26 24 24 24 28 25 3.1. Compute the mean, mode, median, variance, and standard deviation for each group. (1 POINT) 3.2. Graph the histograms. (1 POINT) 3.3. Which group seems to have performed best on the test? (1 POINT) 3.4. Which group appears to be the most homogeneous in terms of manual dexterity? (1 POINT) 4. Thirty eighth grade students were selected from a class of a rural school. A researcher was able to obtain students’ math scores in 7th grade, the teacher’s evaluation scores on students’ academic aptitudes in 8th grade, and students’ final math scores in 8th grade. See the following table for data. Math scores in 7th grade Final math scores in 8th grade Teacher evaluation score 75 43 4 76 44 4 68 36 1 66 38 2 73 41 2 71 40 2 55 27 1 72 46 5 61 38 2 68 35 2 64 31 2 76 42 3 71 45 4 73 41 4 78 45 5 71 41 3 86 50 5 55 34 3 96 51 4 96 54 4 50 28 2 81 50 5 58 37 3 90 46 4 58 23 3 77 45 3 88 55 5 65 34 3 77 54 3 75 54 4 4.1. Run a correlation analysis to examine the relationships among the three variables and interpret the results. (2 POINTS) 5. Given a normal distribution of scores with mean equal to 300 and variance equal to 100, answer the following questions. 5.1. What proportion of scores would fall below 280? (1 POINT) 5.2. What is the probability that a randomly picked score would fall between 310 and 320? (1 POINT) 6. A psychologist rejected the null hypothesis that there is no difference between freshmen and sophomores on drinking behavior. She used a significance level of .05 ( = .05) what is the probability ...

1. Name_______________
1.
A school teacher believes that her kindergarten students have
higher IQ than average children of that age. She decided to test
her hypothesis. The IQ for her class (N=30) was 106, while the
population mean () is 100. The standard deviation for her class
was 10.
1.1.
State the null and research hypothesis ( & ) (1 POINT)
1.2. Write the statistical conclusion, assuming alpha = .05
(Show your calculations). (1 POINT)
1.3.
Based on your decision to reject or fail to reject , what type of
error can you be making? (Choose one) (1 POINT)
Type I error
Type II error
2. A high school teacher correlated the math test scores and
scores on a motivation scale for her 9th graders. She was
delighted to find a high correlation between the two sets of
scores. Later in the semester she correlated the math test scores
of mathematically gifted students who had math scores above
85th percentile and their motivation scores. She found a much

2. lower correlation. What could be the reason for the low
correlation? (1 POINT)
3. Suppose that a performance test of manual dexterity has been
administered to three groups of subjects in different
occupations. The data appear in the table below. Answer the
following questions.
Group1
Group2
Group3
22
23
27
25
26
24
27
28
23
28
22
23
23
27
27
25
26
26
24
23
22
24
27
28

3. 25
27
25
26
25
23
25
23
23
24
28
26
26
27
25
25
25
27
26
27
27
25
27
26
25
28
25
26
24
24
24
28
25
3.1. Compute the mean, mode, median, variance, and standard
deviation for each group. (1 POINT)

4. 3.2. Graph the histograms. (1 POINT)
3.3. Which group seems to have performed best on the test? (1
POINT)
3.4. Which group appears to be the most homogeneous in terms
of manual dexterity? (1 POINT)
4. Thirty eighth grade students were selected from a class of a
rural school. A researcher was able to obtain students’ math
scores in 7th grade, the teacher’s evaluation scores on students’
academic aptitudes in 8th grade, and students’ final math scores
in 8th grade. See the following table for data.
Math scores in 7th grade
Final math scores in 8th grade
Teacher evaluation score
75
43
4
76
44
4
68
36
1
66
38
2
73
41
2
71
40

5. 2
55
27
1
72
46
5
61
38
2
68
35
2
64
31
2
76
42
3
71
45
4
73
41
4
78
45
5
71
41
3
86
50
5
55
34

6. 3
96
51
4
96
54
4
50
28
2
81
50
5
58
37
3
90
46
4
58
23
3
77
45
3
88
55
5
65
34
3
77
54
3
75
54

7. 4
4.1. Run a correlation analysis to examine the relationships
among the three variables and interpret the results. (2 POINTS)
5. Given a normal distribution of scores with mean equal to 300
and variance equal to 100, answer the following questions.
5.1. What proportion of scores would fall below 280? (1
POINT)
5.2. What is the probability that a randomly picked score would
fall between 310 and 320? (1 POINT)
6. A psychologist rejected the null hypothesis that there is no
difference between freshmen and sophomores on drinking
behavior. She used a significance level of .05 ( = .05) what is
the probability of Type I error in this case? (1 POINT)
7. Foa, Rothbaum, Riggs, and Murdock (1991) conducted a
study evaluating four different types of therapy for rape
victims. The Stress inoculation therapy (SIT) group received
instructions on coping with stress. The Prolonged exposure (PE)
group went over the events in their minds repeatedly. The
Supportive counseling (SC) group was taught a general
problem-solving technique. Finally, the Waiting list (WL)
control group received no therapy. The data follow, where the
dependent variable was the severity rating of a series of
symptoms where higher scores indicate more severe symptoms.
Group
n
Mean

8. S.D.
SIT
14
11.07
3.95
PE
10
15.40
11.12
SC
11
18.09
7.13
WL
10
19.50
7.11
The below are the results from an analysis of variance.
7.1. What would happen to the SSgroup, the MSerror, and F if
the sample sizes were twice as large as they actually were, but
all other statistics remained the same? (1 Point)
8.
Y is a measure of math achievement for students in elementary

9. school,, , and are the measures of school, class, and teacher
quality, and , and are the measures of student and parent
backgrounds:
Y (Math)
(School)
(Class)
(Teacher Quality)
(Student)
(Parent)
7.4
7.6
5.32
17.2
2.9
3.43
5.3
5.8
4.88
-1.7

10. 2.0
2.23
7.3
5.9
5.14
22.3
6.9
3.23
8.1
5.8
5.15
24.2
6.5
4.21
7.4
6.1
5.88
16.3
3.0
5.21
6.7
4.1
4.32
16.2
4.5
4.32
8.3
5.0
4.98
22.7
7.7
4.65
6.7
4.9
5.00
9.8

11. 2.5
4.23
8.2
6.2
5.32
19.9
6.5
5.65
7.4
4.8
5.60
10.0
1.0
4.43
4.6
4.2
4.70
-2.9
1.2
2.43
7.0
5.0
4.72
10.9
2.2
4.43
6.9
4.4
4.90
14.8
1.4
4.21
6.6
5.3
5.16
9.0

12. 3.2
4.45
4.5
5.4
5.04
-6.1
1.2
3.54
7.9
6.3
5.01
20.6
6.8
5.65
6.4
7.1
4.96
12.7
4.2
4.54
6.3
5.0
5.11
-1.1
1.7
4.65
8.6
5.4
5.11
25.1
8.6
6.50
8.2
4.7
5.10
22.8

13. 7.7
6.25
8.1. Do the school, class, and teacher measures contribute to the
predictability of Y? (1 POINT) What is the equation? (1
POINT) Report your results with interpretation. (1 POINT)
8.2. Do the student and parent measures contribute to the
predictability of Y? (1 POINT) What is the equation? (1
POINT) Report your results with interpretation (1 POINT)
8.3 Do the student and parent measures contribute to the
predictability of Y beyond that which is predicted by the school,
class, and teacher measures? How do you know? (1 POINT)
9. As shown in the table below, subjects were randomly
assigned to three groups in an experimental study. Group A
received large amounts of praise, Group B received moderate
amounts of praise, and Group C received no praise for correct
answers to math problems. Their scores on an exam are shown
in the table.
Group A
Group B
Group C
7
6
5
8
3
7
4
6
4

14. 7
5
7
3
2
1
3
4
1
9.1. Is there evidence that the scores from the three groups
showed an overall significant difference? If so, what is the
effect size? (2 POINTS)
9.2. If you need further steps to identify which group(s) is (are)
different from each other, please choose an appropriate method
to do so and report and interpret the results (2 POINTS)
10. The Thematic Apperception Test presents subjects with
ambiguous pictures and asks them to tell a story about them.
These stories can be stored in any number of ways. The
researchers asked mothers of 15 normal and 15 schizophrenic
children to complete the TAT, and scored for the number of
stories (out of 10) that exhibited a positive parent-child
relationship. The data follow:
Normal: 8 4 6 4 3 1 4 4 6 4 2 2 6 3 4
Schizophrenic: 2 1 1 3 2 7 2 1 3 1 0 2 4 2 7

15. 10.1.
State the null and research hypothesis ( & ) (1 POINT)
10.2. Is there a significant difference between the normal and
the schizophrenic groups in positive mother-child relationship.
If so, what is the direction and effect size of the difference? (2
POINTS)
11. In a study of 682 college students, respondents were asked
whether or not they had been unfaithful in the context of a
romantic relationship. 103 out of the 480 female respondents
indicated that they had been unfaithful and 53 out of the 202
male respondents indicated that they had been unfaithful. Is
there a statistically significant difference between males’ and
females’ tendency toward relationship infidelity? If so, what is
the direction and effect size of the difference? (2 POINTS)
1
H
Descriptives
SYMPTOMS
14
11.07
3.95
1.06
10
15.40
11.12
3.52
11
18.09

16. 7.13
2.15
10
19.50
7.11
2.25
45
15.62
7.96
1.19
SIT
PE
SC
WL
Total
N
Mean
Std. Deviation
Std. Error
ANOVA
SYMPTOMS
507.840
3
169.280
3.046
.039
2278.738
41
55.579
2786.578
44
Between Groups
Within Groups
Total
Sum of Squares
df

17. Mean Square
F
Sig.
1
X
2
X
3
X
4
X
5
X
5
X
m
0
H