Speed Demons Five people convicted of speeding are ordered to attend a class on driving safety. Before taking the class, a device was installed in their cars to measure driving speed. Their average driving speed was recorded for one week before and after the class. What are the effects, if any, on taking a driving safety class? Before After 65 58 62 65 60 56 70 66 68 60 a) What are the degrees of freedom? What is the critical value based on the type of test (1- or 2- tailed)? df = Critical value = b) Conduct at-test. What are the results? Is there a difference at a = .05? c) Describe the results in plain English. Refer back to the pattern of means. d) Calculate the 95% CI. What do the results suggest about the impact of taking a driving safety test on average driving speed (state in plain English)