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Flashcards in CH 5 Deck (13):
1

Rules of probabilities

1. P(E) must be greater than or equal to 0 and leas than or equal to 1. E = event
2. Sum must = 1

2

Unusual event

Typically less than 5% probability

3

Not so unsual

wide range

4

Certain

Probability of 1

5

Impossible event

Probability of 0

6

P(E) = ?

number of possible outcomes for E / number of total outcomes
N(E)/N(S)

7

E^c = ?

the complement of E (all outcomes in the sample space S that are not outcomes in the event E.

8

General addition rule to find probability

P(E or F) = P(E) + P(F) - P(E and F)

9

Multiplication rule (when E and F are independent)

P(E and F) = P(E) x P(F)

10

Complement rule = at least one

P(E^c) = 1 - P(E)

Example: P(at least 1 nonfiction) = 1 - P(all 4 fiction)

11

Notation P(F| E) = ?

Probability that the event F occurs, given that the event E has occurred.

12

Conditional probability rule

P(F| E) = P(E and F) / P(E)

13

Baye's theorem

P(A and B) = P(A | B) x P(B) = P(B | A) x P(A)