. Mrs. Elliott, a teacher at Durham School of the Arts, studies the effect of "personal narratives" on people's behavior. For example, if the "story" you have about your academic ability is positive, you do better in school than if your "story" is negative. Something as simple as hearing older students describe overcoming challenges similar to yours can help you change your story and improve your performance. (a) Suppose you have 40 college freshman who have volunteered to be part of a study. Design a completely randomized experiment that tests the hypothesis that hearing older students talk about overcoming challenges improves academic performance. Be sure your design addresses how randomization will be incorporated. (b) Suppose you have reason to believe that students with a history of strong academic performance respond differently than those with a history of modest performance. Describe how you would change the experimental design to address this difference.