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A professor states papers are graded using the following categories: excellent, above average, average, and below average. Furthermore, the professor maintains that turned-in papers are graded graciously and offers the following distribution of percentages as an estimate of the manner in which the grades are distributed.
Excellent | Above Average | Average | Below Average |
---|---|---|---|
25% | 35% | 25% | 15% |
A group of students suspects the professor may indeed be generous but only in the perception of being an easy grader. All of the students who had previously taken this professor’s course in the last three years are available, and amazingly, they still have their papers. A random sample of 100 former students is taken, and the actual distribution of evaluations is recorded.
Excellent | Above Average | Average | Below Average |
---|---|---|---|
25% | 35% | 25% | 15% |
O= 20 | O= 25 | O= 30 | 0= 25 |
Note that since the
Find the Test statistics; if the alpha = 0.05
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