The Dean of a Local School Wants to Determine If

Short Answer

The dean of a local school wants to determine if the grade distribution is independent of
the subject matter taught. How many degrees of freedom does this contingency table have?
$$\begin{array} { l l l l l l } \text { Subject } & \mathbf { A } & \mathbf { B } & \mathbf { C } & \mathbf { D } & \mathbf { E } \\\text { Science } & 5 & 11 & 27 & 7 & 11 \\\text { History } & 14 & 18 & 32 & 5 & 7 \\\text { English } & 18 & 35 & 68 & 18 & 23\end{array}$$