An instructor for a stat class of 250 students decided that she was going to curve the exam grades if the average is lower than 80. After grading 50 exams, she observed that the average is 77. She knows that the population standard deviation on this test is 10. She wanted to forecast whether a curve is needed using an appropriate hypothesis testing procedure with ?=0.05
What are the appropriate hypotheses?
What is the critical value she should use?
What's the p-value for the appropriate test?
If she changes the a-level, which of the following will change: the test statistic, the critical value, and/or the p-value? Explain your choice(s).