In a study of mother-infant interaction, mothers are rated by trained observers
ID: 2948877 • Letter: I
Question
In a study of mother-infant interaction, mothers are rated by trained observers on the quality of their interactions with their infants. Mothers were classified on the basis of whether this was their first child or not and whether the infant was low-birth weight (LBW) or full-term (FT). The data represent a score on a 12-point scale, on which a higher score represents better mother-infant interaction. Use alpha = .05.
First Born (X)
(X)2
Not First Born (X)
(X)2
Low Birth weight
6
7
5
8
5
8
4
9
9
8
Sums
Full Term
8
9
7
8
7
9
6
9
7
3
Sums
a. What are your df (you should identify 5 df’s)? What are your critical F’s (there should be 3)?
b. What are the values of your observed F’s (there should be 3)?
c. Based on the above information, would you reject H0, or fail to reject it? Why? What would your conclusions be?
First Born (X)
(X)2
Not First Born (X)
(X)2
Low Birth weight
6
7
5
8
5
8
4
9
9
8
Sums
Full Term
8
9
7
8
7
9
6
9
7
3
Sums
Explanation / Answer
Result:
First Born (X)
(X)2
Not First Born (X)
(X)2
Total
Low Birth weight
6
36
7
49
13
5
25
8
64
13
5
25
8
64
13
4
16
9
81
13
9
81
8
64
17
Sums
29
183
40
322
Full Term
8
64
9
81
17
7
49
8
64
15
7
49
9
81
16
6
36
9
81
15
7
49
3
9
10
Sums
35
247
38
316
Total
64
430
78
638
a. What are your df (you should identify 5 df’s)? What are your critical F’s (there should be 3)?
Total Df = 19
Df for Birth weight = 1
Df for first born = 1
Df for interaction = 1
Df for error = 1
F critical for Birth weight = 4.494
F critical for first born = 4.494
F critical for interaction = 4.494
b. What are the values of your observed F’s (there should be 3)?
F observed for Birth weight = 0.2783
F observed for first born = 3.4087
F observed for interaction = 1.1130
c. Based on the above information, would you reject H0, or fail to reject it? Why? What would your conclusions be?
To test for Birth weight, calculated F=0.2783 < critical F =4.494, Ho is not rejected. We conclude that birth weight is not significantly related.
To test for first born, calculated F=3.4087 < critical F =4.494, Ho is not rejected. We conclude that first born is not significantly related.
To test for interaction, calculated F=1.113 < critical F =4.494, Ho is not rejected. We conclude that interaction is not significant.
ANOVA
Source of Variation
SS
df
MS
F
P-value
F crit
Sample
0.8000
1
0.8000
0.2783
0.6051
4.4940
Columns
9.8000
1
9.8000
3.4087
0.0834
4.4940
Interaction
3.2000
1
3.2000
1.1130
0.3071
4.4940
Within
46.0000
16
2.8750
Total
59.8000
19
First Born (X)
(X)2
Not First Born (X)
(X)2
Total
Low Birth weight
6
36
7
49
13
5
25
8
64
13
5
25
8
64
13
4
16
9
81
13
9
81
8
64
17
Sums
29
183
40
322
Full Term
8
64
9
81
17
7
49
8
64
15
7
49
9
81
16
6
36
9
81
15
7
49
3
9
10
Sums
35
247
38
316
Total
64
430
78
638
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.