Page 235 - Applied Statistics with R
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12.3. ONE-WAY ANOVA 235
boxplot(sleep ~ group, data = melatonin, col = 5:6)
10
8
sleep
6
4
control treatment
group
12.3 One-Way ANOVA
What if there are more than two groups? Consider the model
= + + .
where
∑ = 0
and
2
∼ (0, ).
Here,
• = 1, 2, … where is the number of groups.
• = 1, 2, … where is the number of observations in group .
