
ANOVA
A web designer has recently designed Internet web sites for 3 different clients and is
interested to know whether there is any difference in terms of the number of times the
three sites are accessed. To test this, he samples each site at various times of the day and
records how many times the sites are accessed per minute (measured in “hits” per minute).
The results are given in the following table.
Site 1 Site 2 Site 3
16 18 12
17 21 15
21 24 18
Perform an analysis of variance to determine whether there is any significant difference
in the number of times the three sites are accessed.
i. State the null and alternative hypotheses.
ii. Compute the betweengroup variance (MSB) and the withingroup variance
(MSW).
iii. At α = 0.05, test whether there is any significant difference among the means.