
Chapter 12
418
SSE (sum of squares within samples) =
ij j
j
k
i
n
−
==
∑∑
2
11
where x
ij
is the ith observation in group j,
x
j
the sample mean of group j, k the number of
groups being compared, and n the total number of observations in all the groups.
and MSE (mean square) =
SSE
where SSE is the sum of squares within columns and n – k the degrees of freedom (total
number of observations – number of samples).
3. Calculate total sum of squares: The total variation is equal to the sum of the squared
difference between each observation (sample value) and the grand mean
x
. This is often
referred to as SST (total sum of squares). So, the total ...