Driving school A driving school owner believes that Instructor A is more effective than Instructor B at preparing students to pass the state’s driver’s license exam. An incoming class of 100 students is randomly assigned to two groups, each of size 50. One group is taught by Instructor A; the other is taught by Instructor B. At the end of the course, 30 of Instructor A’s students and 22 of Instructor B’s students pass the state exam.

(a) Do these results give convincing evidence at the a = 0.05 level that Instructor A is more effective?

(b) Describe a Type I and a Type II error in this setting.

Which error could you have made in part (a)?