Chapter 19: 19.9, 19.10, 19.13, 19.14, and 19.16
Chapter 20: 20.5, 20.6, 20.7, and 20.10
Topic 7 – MANOVA Project
Directions: Use the following information to complete the assignment. While APA format is not required for the body of this assignment, solid academic writing is expected, and documentation of sources should be presented using APA formatting guidelines, which can be found in the APA Style Guide, located in the Student Success Center.
A researcher randomly assigns 33 subjects to one of three groups. Group 1 receives technical dietary information interactively from an on-line website. Group 2 receives the same information from a nurse practitioner, while Group 3 receives the information from a video tape made by the same nurse practitioner.
The researcher looked at three different ratings of the presentation; difficulty, usefulness, and importance to determine if there is a difference in the modes of presentation. In particular, the researcher is interested in whether the interactive website is superior because that is the most cost-effective way of delivering the information.
Group
Usefulness
Difficulty
Importance
1
20
5
18
1
25
9
8
1
23
15
20
1
16
9
22
1
20
6
22
1
28
14
8
1
20
6
13
1
25
8
13
1
24
10
24
1
18
10
20
1
17
9
4
2
28
7
14
2
25
14
5
2
26
9
20
2
19
15
22
2
29
14
12
2
15
6
2
2
29
10
5
2
26
11
1
2
22
5
2
2
15
15
14
2
29
6
4
2
15
6
3
3
22
8
12
3
27
9
14
3
21
10
7
3
17
9
1
3
16
7
12
3
19
9
7
3
23
10
1
3
27
9
5
3
23
9
6
3
16
14
22
1. Run the appropriate analysis of the data and interpret the results.
2. How could this study have been done differently? Why or why not would this approach be better?
PSY5
20
– Module
7
A
nswer Sheet
Submit your answers in the boxes provided. No credit will be given for responses not found in the correct answer area.
C
hapter 19:
19.9 Randomly selected records of
1
40
convicted criminals reveal that their crimes were committed on the following days of the week:
D AYS W H E N CR I MES WERE COMMITTED |
|||||||||||
F REQUENCY |
MON. |
TUE. |
WED. |
THU. |
FRI. |
SAT. |
SUN. |
TOTA L |
|||
Observed (ƒₒ) |
17 |
21 |
22 |
1 8 |
23 |
24 |
15 |
14
0 |
Question: |
Calculations or Logic: |
Answer: |
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Using the .01 level of significance, test the null hypothesis that in the underlying population, crimes are equally likely to be committed on any day of the week. |
Step 1 |
What is the research problem? |
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Step 2 |
What is the null hypothesis? |
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What is the alternative hypothesis? |
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Step 3 |
What are the degrees of freedom? |
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What is the decision rule? |
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Step 4 |
What is the critical X2? |
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What is the value of X2? (you will need to calculate this) |
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Step 5 |
What is the decision? (retain or reject the null hypothesis at the specified level of significance; note the relationship between the observed and critical X2 scores) |
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Step 6 |
What is your interpretation of the decision in relation to the original research problem? |
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Specify the p -value for this test result. |
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How might this result be reported in the literature? |
19.
10
While playing a coin-tossing game in which you are to guess whether heads or tails will appear, you observe
30
heads in a string of
50
coin tosses.
Test the null hypothesis that this coin is unbiased, that is, that heads and tails are equally likely to appear in the long run. |
19.13 In 19
12
, over 800 passengers perished after the ocean liner Titanic collided with an iceberg and sank. The table below compares the survival frequencies of cabin and steerage passengers.
ACCOMMODATIONS ON THE TITANIC |
||||
SURVIVED |
CA B IN |
STEERA G E |
TOTAL |
|
YES |
29 9 |
1 86 |
4 85 |
|
NO |
28 0 |
52 6 |
806 |
|
5 79 |
71 2 |
12 91 |
Source: MacG. Dawson, R .
J
. (19
95
). The “unusual” episode data revisited. Journal of Statistical Education, 3, no. 3.
Using the .05 level of significance, test the null hypothesis that survival rates are independent of the passengers’ accommodations (cabin or steerage). |
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Assuming a significant x², estimate the strength of the relationship. |
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What is the strength of this relationship? (small, medium, large or very large)? |
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To more fully appreciate the importance of this relationship, calculate an odds ratio to determine how much more likely a cabin passenger is to have survived than a steerage passenger. |
19.14 In a classic study, Milgram et al. “lost” stamped envelopes with fictitious addresses (
Medical Research Association
,
Personal Address
,
Friends of Communist Party
, and
Friends of Nazi Party
).* One hundred letters with each address were distributed among four locations (shops, cars, streets, and phone booths) in New Haven Connecticut, with the following results:
ADDRESS |
RETURNED |
NOT RETURNED |
|||||||||
Medical Research Association |
72 |
28 |
100 |
||||||||
Personal Address | 71 |
2
9 |
|||||||||
Friends of Communist Party |
25 |
75 |
|||||||||
Friends of Nazi Party | |||||||||||
Total |
1 93 |
207 |
400 |
*Milgram, S., Mann, L., & Harter, L. (1965). The Lost Letter Technique: A Tool of
Social Research. Public Opinion Quarterly, 29,
43
7–438.
Using the .05 level of significance, test the null hypothesis that address does not matter in the underlying population. |
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Specify the approximate p -value for this result. |
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How might these results be reported in the literature? |
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Collapse the original 4 x 2 table to a 2 x 2 table by combining the results for the two neutral addresses and for the two inflammatory addresses. Calculate the odds ratio for returned letters. |
19.16 A social scientist cross-classifies the responses of 100 randomly selected people on the basis of gender and whether or not they favor strong gun control laws to obtain the following:
GENDER AND ATTITUDE TOWARD STRONG GUN CONTROL |
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ATTITUDE TOWARD GUN CONTROL |
||||||
GENDER |
FAVOR |
OPPOSE |
||||
MALE |
40 | 20 |
60 |
|||
FEMALE |
30 |
10 |
||||
70 |
Using the .05 level of significance, test the null hypothesis for gender and attitude toward gun control. |
Chapter 20:
20.5 A group of high-risk automobile drivers (with three moving violations in one year) are required, according to random assignment, either to attend a traffic school or to perform supervised volunteer work. During the subsequent five-year period, these same drivers were cited for the following number of moving violations:
NUMBER OF MOVING VIOLATIONS |
|
TRAFFIC SCHOOL |
VOLUNTEER WOR K |
0 0 15 9 23 7 |
26 7 14 6
|
Why might the Mann-Whitney U test be preferred to the t test for these data? |
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Use U to test the null hypothesis at the .05 level of significance. |
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What is the sample size? |
Group 1: |
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Group 2: |
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What is the sum of ranks? |
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What is the critical U? |
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What is the value of U? (you will need to calculate this) |
U1: |
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U2: |
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U: |
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What is the decision? (retain or reject the null hypothesis) |
20.6 A social psychologist wishes to test the assertion that our attitude toward other people tends to reflect our perception of their attitude toward us. A randomly selected member of each of 12 couples who live together is told (in private) that his or her partner has rated that person at the high end of a 0 to 100 scale of trustworthiness. The other member is told (also in private) that this or her partner has rated that person at the low end of the trustworthiness scale. Each person is then asked to estimate, in turn, the trustworthiness of his or her partner, yielding the following results. (According to the original assertion, the people in the trustworthy condition should give higher ratings than should their partners in the untrustworthy condition.)
TRUSTWORTHINESS RATINGS |
|||
COUPLE |
TRUSTWORTHY (1) |
UNTRUSTWORTHY (2) |
|
A | |||
B |
35 |
||
C | 50 |
55 |
|
D | 93 | ||
E |
74 |
12 | |
F |
47 |
34 |
|
G | 95 | ||
H |
63 |
||
I |
44 |
43 | |
J |
88 |
79 | |
K |
56 |
33 |
|
L | 86 |
Use T to test the null hypothesis at the .01 level. |
|
What is n? |
|
What is the critical T? |
|
What is the value of T? (you will need to calculate this) |
R+: |
R-: |
|
T: |
20.7 Does background music influence the scores of college students on a reading comprehension test? Sets of 10 randomly selected students take a reading comprehension test with rock, country, or classical music in the background. The results are as follows (higher scores reflect better comprehension):
READING COMPREHENSION SCORES |
|||
ROCK (1) |
COUNTRY (2) |
CLASSICAL (3) |
|
90 |
99 |
52 | |
11 |
94 |
||
82 |
91 | ||
67 |
|||
98 |
97 |
||
81 |
31 |
||
73 |
83 |
||
85 | |||
87 |
|||
84 |
77 |
69 |
Why might the H test be preferred to the F test for these data? |
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Use H to test the null hypothesis at the .05 level of significance. |
|
What is the critical H? |
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What is the value of H? (you will need to calculate this) |
20.10 Use H rather than F to test the weight change data recorded in Review Question 16.13 on page 381.
Use H rather than F to test the weight change data. |