Three-group mean comparison
- Input
- A: 8, 9, 6, 7; B: 10, 11, 9, 12; C: 5, 7, 6, 8.
- Method
- Partition total variability into between-group and within-group sums of squares.
- Formula
- F = MS_between / MS_within
- Intermediate steps
- Group means are compared with the grand mean
- df_between = k - 1
- df_within = n - k
- Final result
- The tool returns an ANOVA table with F statistic and p-value.
- Interpretation
- A significant omnibus F test means at least one group mean differs under assumptions.
- Limitation
- It does not identify which pair of groups differs.