Probability Flashcards
(13 cards)
Probability
How we quantify uncertainty/randomness
Disjoint Events
Mutually exclusive
Non-disjoint Events
Can co-occur
Independent
Occurrence of 1 event not tell us anything about probability of other event also occurring
Dependent
Occurrence of 1 event related to probability of other event also occurring
Complement Events
The complement to event A are all events not included in event A
Are disjoint events independent or dependent?
Dependent
Addition Rule (disjoint events)
P (A or B) = P(A) + P(B)
Addition Rule (non-disjoint events)
P (A or B) = P(A) + P(B) - P (A and B)
Multiplication Rule (independent events)
P (A and B) = P(A) * P(B)
How to account for drawing an observation from a total w/o replacement?
decreases n in bottom
12/100 * 23/99 instead of 23/100
How to determine if events are independent?
Compare expected P (A and B) (from calculations) to actual
When to use General Multiplication Rule? What is it?
Finds probability of 2 events co-occurring regardless of relationship
- P (A and B) = P (A given B) * P(B)