Data from Chapter 6, Table 6.1, page 121
input a comfort 1 16 1 11 1 22 1 8 1 15 1 6 1 16 1 15 1 12 1 11 2 10 2 5 2 8 2 12 2 0 2 16 2 8 2 12 2 10 2 6 3 9 3 3 3 4 3 8 3 8 3 6 3 13 3 5 3 9 3 7 4 9 4 12 4 12 4 4 4 5 4 10 4 7 4 12 4 9 4 8 5 11 5 9 5 10 5 13 5 13 5 12 5 11 5 18 5 14 5 12 end
Table 6.1, page 121. Analysis of variance in a one-way design
oneway comfort a
Analysis of Variance
Source SS df MS F Prob > F
------------------------------------------------------------------------
Between groups 264.92 4 66.23 5.22 0.0015
Within groups 571 45 12.6888889
------------------------------------------------------------------------
Total 835.92 49 17.0595918
Bartlett's test for equal variances: chi2(4) = 5.3645 Prob>chi2 = 0.252
Pairwise Comparison (Tukey WSD): Section Section 6.4, page 120-128
prcomp comfort a, tukey
Pairwise Comparisons of Means
Response variable (Y): comfort
Group variable (X): a
Group variable (X): a Response variable (Y): comfort
------------------------------- -------------------------------
Level n Mean S.E.
------------------------------------------------------------------
1 10 13.2 1.451436
2 10 8.7 1.398809
3 10 7.2 .9165151
4 10 8.8 .9043107
5 10 12.3 .7895146
------------------------------------------------------------------
Simultaneous confidence level: 95% (Tukey wsd method)
Homogeneous error SD = 3.562147, degrees of freedom = 45
95%
Level(X) Mean(Y) Level(X) Mean(Y) Diff Mean Confidence Limits
-------------------------------------------------------------------------------
2 8.7 1 13.2 -4.5 -9.02666 .0266604
3 7.2 1 13.2 -6 -10.52666 -1.47334
2 8.7 -1.5 -6.02666 3.02666
4 8.8 1 13.2 -4.4 -8.92666 .1266604
2 8.7 .1 -4.42666 4.62666
3 7.2 1.6 -2.92666 6.12666
5 12.3 1 13.2 -.9 -5.42666 3.62666
2 8.7 3.6 -.9266604 8.12666
3 7.2 5.1 .5733396 9.62666
4 8.8 3.5 -1.02666 8.02666
-------------------------------------------------------------------------------
Post-Hoc Error Correction (Scheffe) : Section 6.5, page 128-130
oneway comfort a, scheffe
Analysis of Variance
Source SS df MS F Prob > F
------------------------------------------------------------------------
Between groups 264.92 4 66.23 5.22 0.0015
Within groups 571 45 12.6888889
------------------------------------------------------------------------
Total 835.92 49 17.0595918
Bartlett's test for equal variances: chi2(4) = 5.3645 Prob>chi2 = 0.252
Comparison of comfort by a
(Scheffe)
Row Mean-|
Col Mean | 1 2 3 4
---------+--------------------------------------------
2 | -4.5
| 0.111
|
3 | -6 -1.5
| 0.013 0.925
|
4 | -4.4 .1 1.6
| 0.126 1.000 0.907
|
5 | -.9 3.6 5.1 3.5
| 0.988 0.293 0.051 0.321