A Teacher Finds That Final Grades in the Statistics Department

Short Answer

A teacher finds that final grades in the statistics department are distributed as: A, 25%; B, 25%; C, 40%; D, 5%; F, 5%. At the end of a randomly selected semester, the following grades were recorded. Find the rejection region used to determine if the grade distribution for the department is different than expected. Use α = 0.01. $\begin{array}{l|lllll}\text { Grade } & \text { A } & \text { B } & \text { C } & \text { D } & \text { F } \\\hline \text { Number } & 42 & 36 & 60 & 14 & 8\end{array}$

A) $\chi ^ { 2 } > 13.277$
B) $\chi ^ { 2 } > 11.143$
C) $\chi ^ { 2 } > 9.488$
D) $x ^ { 2 } > 7.779$