A brief disclaimer: the views and ideas shared on this page do not reflect the opinions of the US Peace Corps or any other entity related to the US government.

Saturday, January 5, 2013

My Final Exam [1/5]


Let me refer you to Figure 1.1, below.


Figure 1.1 shows the probability distribution of a student’s grade on a 20-question, 4-option (ie select A, B, C, or D) multiple choice test, given that he/she didn’t study or even read the questions.  That means the grade you’d expect with strictly random guessing.  Notice two things: even without reading the questions, you’re most likely to score a 5/20, which means you’ll pick the correct answer 1 out of 4 times.  Makes sense!  Notice the probability of scoring a 0 – ie being so unlucky that you don’t choose the right option even once – is just above 0%.  To be exact, it’s 0.3%.  The odds of getting a 0 on my final exam is a third of 1 percent, GIVEN THAT YOU DIDN’T STUDY OR EVEN READ THE QUESTIONS.  One student did it.  And to make matters worse, I gave out the exam a week before they took it.

Cheers to all the teachers out there who still fight the fight anyway.

No comments:

Post a Comment