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Tuesday, November 12 Analysis of Variance. Tuesday, November 12 The Analysis of Variance. Tuesday, November 12 The Analysis of Variance. ANOVA. Between-group variance estimate. F =. within-group variance estimate. _. SS T = (X - X) 2 SS B = N G (X G - X) 2 - PowerPoint PPT Presentation
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Tuesday, November 12
Analysis of Variance
Tuesday, November 12
The Analysis of Variance
Tuesday, November 12
The Analysis of VarianceANOVA
151149N =
SEX
21
RD
G
80
70
60
50
40
30
20
7515669N =
SES
321
RD
G
80
70
60
50
40
30
20
7515669N =
SES
321
RD
G
80
70
60
50
40
30
20
214321737N =
RACE
4321
RD
G
80
70
60
50
40
30
20
174
91
242
237
213
F = Between-group variance estimate
within-group variance estimate
SST = (X - X)2
SSB = NG (XG - X)2
SSW = (X1 - X1)2 +
(X2 - X2)2 + •••• (Xk - Xk)2
SST = SSB + SSW
_
_ _
__
_
F = Between-group variance estimate
within-group variance estimate
MSB = SSB / dfB
MSW = SSW / dfW
where
dfB = k-1 (k = number of groups)dfW = N - k
Protected t-test
t = Xi - Xj
MSW ( 1/Ni + 1/Nj)
__
Where df = N - k
= dfB (F - 1)
dfB F + dfW
Epison bears the same relationship to F that rpb bears to t.
