The target grade distribution for a particular course is 10% A, 30% B, 40% C, 15% D, 5% F.Students complain that a particular professor who teaches this course grades "too hard." The present students survey 250 former students of this professor's class and then do a χ2 goodness-of-fit test to see if the data provide sufficient evidence to support their complaint.They find a critical value of 14.7 and a test statistic of 9.8, with α = 0.10.What is the take-away conclusion from this survey?
A) The professor's grades do not conform to the target.
B) The professor's grades conform to the target.
C) There is not sufficient statistical evidence to reject the idea that the professor's grades conform to the target.
D) There is sufficient statistical evidence to reject the idea that the professor's grades conform to the target.

Question

Quizplus · Accepted Answer

Since the test statistic (9.8) is less than the critical value (14.7), and the level of significance (α) is 0.10 (which is greater than the p-value), we fail to reject the null hypothesis that there is no significant difference between the observed grade distribution and the target grade distribution. Therefore, there is not sufficient statistical evidence to support the claim that the professor's grades do not conform to the target. Therefore, answer choice C is the correct answer.

The Target Grade Distribution for a Particular Course Is 10