Module 2: Probability
Probability is the study of uncertainty and randomness in the world. It measures chance.
Proportion is a summary statistic. Proportion measures size (i.e. how many patients have optional blood pressure).
- We show the probability of Event A as P(A)
- The compliment of an event, or chance of event not occurring is AC
- P(A) + P(AC) = 1
- Two events are mutually exclusive (or "disjoint") if when one event occurs the other cannot
- Joint Probability = P(A & B) = P(A,B) = P(A ꓵ B)
- P(A or B) = P(A U B)
- When A and B are non-mutually exclusive P(A or B) = P(A) + P(B) - P(A & B)
- When A and B are mutually exclusive events P(A or B) = P(A) + P(B) since P(A&B)=0
