is a nonparametric
test that is used to test equality
of variance when when there are two or more
samples. The hypothesis
for Levene's test is:
H0 the samples are drawn from
populations with equal variances
H1 the variance of at least
one of the populations is different
The test uses the statistic 'W' where:
||total number of values
||number of values in row 'i'
||number of levels
||median of level 'i'
||the average of all the zij
||the average of the zij
values in row 'i'
method relies on the assumption that the
variance is the same for all the samples.
Levene's test can be used to check this.