A Teacher Figures That Final Grades in the Chemistry Department $x _ { 0 } ^ { 2 }$

Multiple Choice

A teacher figures that final grades in the chemistry department are distributed as: A, 25 % ; B, 25 % ; C, 40 % ; D, 5 % ; F, 5 % . At the end of a randomly selected semester, the following number of grades were recorded. Find the critical value $x _ { 0 } ^ { 2 }$ to determine if the grade distribution for the department is different than expected. Use $\alpha$

=0.01 .
$\begin{array} { l | l l l l l } \text { Grade } & \text { A } & \text { B } & \text { C } & \text { D } & \text { F } \\\hline \text { Number } & 36 & 42 & 60 & 8 & 14\end{array}$

A) 13.277
B) 15.086
C) 9.488
D) 7.779