Consider an experiment with treatment factors A and B, with factor $\mathrm{A}$ having five levels and factor $\mathrm{B}$ having six levels. The results of the experiment are summarized in the following analysis of variance table:
$$
\begin{array}{lcc}
\hline \text { Source of Variation } & \begin{array}{c}
\text { Sum of } \\
\text { Squares }
\end{array} & \begin{array}{c}
\text { Degrees of } \\
\text { Freedom }
\end{array} \\
\hline \text { Treatment A groups } & 86 & 4 \\
\text { Treatment B groups } & 75 & 5 \\
\text { Interaction } & 75 & 20 \\
\text { Error } & 300 & 90 \\
\text { Total } & 536 & 119 \\
\hline
\end{array}
$$