Question: how to calculate ssw anova?
Answer: Use the formula SST – SSB to find the SSW, or the sum of squares within groups. Figure the degrees of freedom for between the groups, “dfb,” and within the groups, “dfw.” The formula for between groups is dfb = 1 and for the within groups it is dfw = 2n-2. Compute the mean square for the within groups, MSW = SSW / dfw.