User Guide

368
Chapter 21
Assumptions. Each group is an independent random sample from a normal population.
Analysis of variance is robust to departures from normality, although the data should
be symmetri
c. The groups should come from populations with equal variances. To
test this assumption, use Levene’s homogeneity-of-variance test.
Figure 21-1
One-Way ANO
VA output
1596.00 2 798.00 7.824 .005
1530.00 15 102.00
3126.00 17
Between
Groups
Within
Groups
Total
Absorbed
Grams of
Fat
Sum of
Squares
df
Mean
Square
F Significance
ANOVA
6 72.00 13.34 5.45 58.00 86.00 56 95
6 85.00 7.77 3.17 76.84 93.16 77 97
6 62.00 8.22 3.36 53.37 70.63 49 70
18 73.00 13.56 3.20 66.26 79.74 49 97
Peanut Oil
Lard
Corn Oil
Total
Type
of Oil
Absorbed
Grams of
Fat
N Mean
Std.
Deviation
Std. Error
Lower
Bound
Upper
Bound
95% Confidence Interval
for Mean
Minimum Maximum
Descriptives
-.5 1 -.51Contrast
Peanut Oil Lard Corn Oil
Type of Oil
Contrast Coefficients
18.00 5.05 3.565 15 .003
18.00 4.51 3.995 12.542 .002
1Contrast
1Contrast
Assume equal variances
Does not assume equal variances
Absorbed
Grams of Fat
Value of
Contrast
Std. Error t df
Significance
(2-tailed)
Contrast Tests