A Test That Curves Itself
A final exam of 'write your name' plus guessing 20 coin flips produces a perfect bell curve centered at 75.
Use this cartoon
Free for classrooms, worksheets, slides and other non-commercial use under CC BY-NC 4.0, with credit to Ben Orlin.
Cartoon by Ben Orlin, Math with Bad Drawings. https://cartoons.mathwithbaddrawings.com/2019-02-14-a-test-that-curves-itself/ (CC BY-NC 4.0)Transcript
[Final Exam] "1. Write your name (50 points). 2. I am going to flip 20 coins. Guess the results. (2.5 points each)"
Students: "Professor, this test is totally arbitrary and unfair!"
Professor: "Ridiculous! The scores always make a perfect bell curve!" [bell curve from 50 to 100, centered at 75]