Two accounting professors decided to compare the variance of their grading procedures. To accomplish this,they each graded the same 10 exams,with the following results: At the 10% level of significance,what is the decision regarding the null hypothesis?
A)Reject the null hypothesis and conclude the variances are different.
B)Fail to reject the null hypothesis and conclude no significant difference in the variances.
C)Reject the null hypothesis and conclude the variances are the same.
D)Fail to reject the null hypothesis and conclude the variances are the same.

Question

Two accounting professors decided to compare the variance of their grading procedures. To accomplish this,they each graded the same 10 exams,with the following results:  At the 10% level of significance,what is the decision regarding the null hypothesis?
A)Reject the null hypothesis and conclude the variances are different. 
B)Fail to reject the null hypothesis and conclude no significant difference in the variances. 
C)Reject the null hypothesis and conclude the variances are the same. 
D)Fail to reject the null hypothesis and conclude the variances are the same.

Quizplus · Accepted Answer

To test the null hypothesis that the variances are equal, we can use the F-test. Based on the given data, the F-value is calculated to be 7.29. With 9 degrees of freedom in the numerator and denominator, the critical value at the 10% level of significance is 3.17. Since 7.29 is greater than 3.17, we reject the null hypothesis and conclude that the variances are different. Therefore, the answer is choice A.

Two Accounting Professors Decided to Compare the Variance of Their