Exam II results

So the exam results are in (except for a couple of you that had a reason to make it up late). You will get your exams back tomorrow.

The raw average was 70.7%, with a standard deviation of 18.5. Not to bad, but the spread was too high. I scaled the overall result to have an average of 80%, with a standard deviation of 12.5%, which makes the distribution more comparable to the last exam and a bit more fair I think. Here is what that looks like:

If we look at the average score by question, and the number that chose to respond (recall you had to pick 8 of 12 questions), it is easy to see which questions you perceived as being more difficult. Moreover, the second plot shows that your instincts were, as a whole, correct: questions perceived as more difficult (fewer people trying them) had a lower score on average.


Apparently, questions 6 and 7 were just mean. Maybe question 3 as well, but that was taken almost verbatim from the homework.

Anyway: you all did better than you think. Below is the breakdown by letter grade. Full exam solutions should be out by week's end.

A: 12
B: 11
C: 14
D: 5
F: 4