Directions: The purpose of Project 8 is to prepare you for the final, comprehensive exam and is set up EXACTLY the same. Questions 1 and 2 are not graded in this exercise, but are on the final. Be sure to answer them still so you can receive feedback. Once done with these, move into the calculation questions. Be advised that you will need to decide which type of test to use in most of the problems. Please write out all pertinent information for each of the 4 steps of hypothesis testing. For the calculations, you only need to provide the values of all statistics for that test. There is no need to show work. List the four Steps of the Hypothesis test: Step 1 – Step 2 – Step 3 – Step 4 – This semester we have discussed the following statistical analyses. Z-test One-Sample t -test Independent Groups t -test Repeated Measures t -test One-Way ANOVA Repeated Measures ANOVA Correlation When do you use them? Please type your answer in the Test Used column. ơ is given µ is given Groups Compared Test Used No No Looks at the same group at 2 different times or across two different conditions Yes Yes Sample against population Examines the degree to which two variables relate to one another No No Looks at the same group at 2 or more times or across 2 or more conditions No No Examines mean differences between two different groups No Yes Sample against population No No Examines mean differences between 2 or more groups 1. A researcher for a cereal company wanted to demonstrate the health benefits of eating oatmeal. A sample of 9 volunteers was obtained and each participant ate a fixed diet without any oatmeal for 30 days. At the end of the 30-day period, cholesterol was measured for each individual. Then the participants began a second 30-day period in which they repeated exactly the same diet except that they added 2 cups of oatmeal each day. After the second 30-day period, cholesterol levels were measured again and the researcher recorded the difference between the two scores for each participant. For this sample, cholesterol scores average M = 16 points lower with the oatmeal diet with SS = 538 for the difference scores. 10 points · Are the data sufficient to indicate a significant change in cholesterol level? Use a two-tailed test with α = .01. · Compute r 2 to measure the size of the treatment effect. 2. One possible explanation for why some birds migrate and others maintain year round residency in a single location is intelligence. Specifically, birds with smaller brain, relative to their body size, are not simply smart enough to find food during the winter and must migrate to warmer climates where food is easily available. Birds with bigger brains, on the other hand, are more creative and can find food even when the weather turns harsh. Following are hypothetical data similar to the actual results. The numbers represent relative brain size for the individual birds in each sample. 10 points Non-Migrating S.

1. Directions: The purpose of Project 8 is to prepare you for the
final, comprehensive exam and is set up EXACTLY the same.
Questions 1 and 2 are not graded in this exercise, but are on the
final. Be sure to answer them still so you can receive feedback.
Once done with these, move into the calculation questions.
Be advised that you will need to decide which type of test to use
in most of the problems. Please write out all pertinent
information for each of the 4 steps of hypothesis testing. For the
calculations, you only need to provide the values of all statistics
for that test. There is no need to show work.
List the four Steps of the Hypothesis test:
Step 1 –
Step 2 –
Step 3 –
Step 4 –
This semester we have discussed the following statistical
analyses.
Z-test
One-Sample
t
-test
Independent Groups
t
-test

2. Repeated Measures
t
-test
One-Way ANOVA
Repeated Measures ANOVA
Correlation
When do you use them? Please type your answer in the Test
Used column.
ơ is given
µ is given
Groups Compared
Test Used
No
No
Looks at the same group at 2 different times or across two
different conditions
Yes
Yes
Sample against population
Examines the degree to which two variables relate to one
another
No
No
Looks at the same group at 2 or more times or across 2 or more
conditions
No

3. No
Examines mean differences between two different groups
No
Yes
Sample against population
No
No
Examines mean differences between 2 or more groups
1. A researcher for a cereal company wanted to demonstrate the
health benefits of eating oatmeal. A sample of 9 volunteers was
obtained and each participant ate a fixed diet without any
oatmeal for 30 days. At the end of the 30-day period,
cholesterol was measured for each individual. Then the
participants began a second 30-day period in which they
repeated exactly the same diet except that they added 2 cups of
oatmeal each day. After the second 30-day period, cholesterol
levels were measured again and the researcher recorded the
difference between the two scores for each participant. For this
sample, cholesterol scores average M = 16 points lower with the
oatmeal diet with SS = 538 for the difference scores.
10 points
·
Are the data sufficient to indicate a significant change in
cholesterol level? Use a two-tailed test with α = .01.
·
Compute r
2
to measure the size of the treatment effect.

4. 2. One possible explanation for why some birds migrate and
others maintain year round residency in a single location is
intelligence. Specifically, birds with smaller brain, relative to
their body size, are not simply smart enough to find food during
the winter and must migrate to warmer climates where food is
easily available. Birds with bigger brains, on the other hand, are
more creative and can find food even when the weather turns
harsh. Following are hypothetical data similar to the actual
results. The numbers represent relative brain size for the
individual birds in each sample.
10 points
Non-Migrating
Short-Distance Migrants
Long Distance Migrants
18
6
4
13
11
9
19
7
5
N
= 18
12
9
6
G
= 180
16

5. 8
5
ΣX
2
= 2150
12
13
7
M
= 15
M
= 9
M
= 6
T
= 90
T
= 54
T
= 36
SS
= 48
SS
= 34
SS
= 16
·
Determine whether there are any significant differences among
the three groups of birds.
·
Compute the effect size for these data.

6. 3. In 1974, Loftus and Palmer conducted a classic study
demonstrating how the language used to ask a question can
influence eyewitness memory. In the study, college students
watched a film of an automobile accident and then were asked
questions about what they saw. One group was asked, “About
how fast were the cars going when they smashed into each
other?” Another group was asked the same question except the
verb was changed to “hit” instead of “smashed into.” The
“smashed into” group reportedly significantly higher estimates
of speed than the “hit” group. Suppose a researcher repeats this
study with a sample of today’s college students and obtains the
following results.
10 points
Estimated Speed
Smashed Into
Hit
n
= 15
n
= 15
M
= 40.8
M
= 34.0
SS
= 510
SS
= 414
·
Do the results indicate a significantly higher estimate for speed

7. for the “smashed into” group? Use a one-tailed test with α =
.01.
·
Calculate the effect size.
4. For the following set of scores, compute the Pearson
correlation. Then, state whether or not you can reject the null
hypothesis assuming a one-tailed test with α = .05.
10 points
X
Y
6
4
3
1
5
0
6
7
4
2
6
4
5. In a study examining the effect of alcohol on reaction time,
researchers found that even moderate alcohol consumption

8. significantly slowed response time to an emergency situation in
a driving simulation. In a similar study, researchers measured
reaction 30 minutes after participants consumed one 6-ounce
glass of wine. Again, they used a standardized driving
simulation task for which the regular population averages
u
= 400 msec. The distribution of reaction times is approximately
normal with σ = 40. Assume that the researcher obtained a
sample mean of
M
= 422 for the
n
= 25 participants in the study.
5 points
·
Are the data sufficient to conclude that the alcohol has a
significant effect on reaction time? Use a two-tailed test with α
= .05.
·
Do the data provide evidence that the alcohol significantly
increased (slowed) reaction time? Use a one-tailed test with α =
.05.
·
Compute Cohen’s
d
to estimate the size of the effect.
6. The following data are from an experiment comparing three
different treatment conditions for each of 5 people (i.e. each
person was exposed to condition A, B, and C during the

9. study):
10 points
A
B
C
0
1
2
2
5
5
N
= 15
1
2
6
5
4
9
ΣX
2
= 354
2
8
8
T
= 10
T
= 20
T
= 30
SS
= 14

10. SS
= 30
SS
= 30
·
Using an α = .05, determine whether there are significant mean
differences among the three conditions.
·
Computer the effect size for the study.
7. Researchers report that students who were given questions to
be answered while studying new material had better scores
when tested on the material compared to students who were
simply given an opportunity to reread the material. In a similar
study, an instructor in a large psychology class gave one group
of students questions to be answered while studying for the
final exam. The overall average for the exam was µ = 73.4, but
the
n
= 16 students who answered questions had a mean of
M
= 78.3 with a standard deviation of
s
= 8.4. For this study, did answering questions while
studying produce significantly higher exam scores? Use a one-
tailed test with α = .01.
5 points

11. Extra Credit
Complete the following ANOVA summary table.
2 points
n =
6;
k
= 4
Source
SS
Df
MS
F
Between
60
Within
Between Subjects
Error
14

12. Total
122
For the following test statistics that you obtained in Step 3 of
the Hypothesis test, state whether the score falls in the critical
region or not. Note that to receive credit for these problems you
MUST
give the critical value you used to make your decision in the
appropriate column. No calculations are needed for this
question. I want you to demonstrate that you know how to use
the tables and understand how to make a correct decision.
2 points
Test Statistic Obtained
Information needed to determine Critical values
Critical Value from the appropriate table
Should you
RETAIN
or
REJECT
the null by stating either word.
z
= +2.65
α = .05; two=tailed
t
= +3.15
α = .01, two-tailed; df = 3

13. r
= .619
α = .01, one-tailed; df =14
Examine the following decisions researchers have made about
their experiments. Was the correct decision made? If not, did
they commit Type I or Type II error? You may want to check to
make sure they looked up the correct critical value first.
2 points
Test Statistic Obtained by the Researcher
Critical Value He/She Looked Up
The Decision They Made
Is the decision correct?
If not, did they make a
Type I
or
Type II
error. You cannot answer no without indicating which type of
error first.
t
= 1.95
α = .05, one-tailed; df = 19
t
crit
= 1.729
Retain the null or

14. Fail to reject the null
F
(4,10) = 5.86, α = .01
F
crit
= 5.99
Reject the null
End Project 8:
Remember that Exam 5 will look exactly like this. Use it to
prepare and do other practice problems from each chapter.