§ odds ratio and relative risk
Settings:
- There are 2000 students in the campus. (composition shown in table)
- In practice we cannot study all of the 2000 students. And we must do sampling.
Ground truth
| exercise (E) | no exercise (Ne) | Sum | |
|---|---|---|---|
| Pass Exam (P) | 500 | 700 | 1200 |
| Fail Exam (F) | 46 | 754 | 800 |
| Sum | 546 | 1454 | 2000 |
Thesis: not going to exercise increases risk of failing the exam.
A lecturer wants to study the Relative Risk of failing exam for student to do not go to exams.
$$ \begin{aligned} RR &= \frac{F_{Ne}}{P_{Ne} + F_{Ne}} : \frac{F_{E}}{P_{E} + F_{E}}\\\\ \end{aligned} $$