Question

Professor Fair believes extra time does not improve grades on exams. He randomly divided a group of 300 students into two groups and gave them all the same test. One group had exactly 1 hour in which to finish the test, and the other group could stay as long as desired. The results follow. Test at the 0.01 level of significance that time to do a test and test results are independent.

           

	Exam Grades
Time	A	B	C	F	Row Total
1 hour	23	42	65	12	142
Unlimited	17	48	85	8	158
Column Total	40	90	150	20	300

A. What is the null hypothesis?

B. What is the alternative hypothesis?

C. What distribution are you using?

D. What test are you running?

E. What is your conclusion?

Answer 1