2. Probability Models
Vocabulary terms: Please review the definitions of these terms. They are a
review of what you have learned in Algebra, Geometry and Algebra II/Trig:
1. Probability
2. Probability Model
3. Sample Space
4. Event
5. Subset
6. Empty Set
7. Independent Events
8. Disjoint Events
9. Dependent Events
10.Joint Events
11.Tree Diagram
12.With Replacement
13.Without Replacement
14.Complement of an Event
15.Conditional Probability
3. 6 General Probability Rules
1.) 0≤P(A)≤1 The probability that an event will occur is between 0 and 1
inclusively
2.) P(S) = 1 The sum of the probabilities of all possible outcomes of an
event is always 1
3.) P(A or B) = P(A) + P(B) - P(A∩B)
The probability that event A or event B will happen is equal to the
probability that event A happens, plus the probability the event B happens
minus the probability of A and B happening simultaneously.
4.) P(AC) = 1-P(A) The probability of the complement of event A happening
is equal to 1 minus the probability of A happening
5.) P(A and B) = P(A)*P(B) if A and B are independent
The probability of event A and event B happening simultaneously is equal
to the probability that event A happens multiplied by the probability that
event B happens
6.) P(A or B or C) = P(A) + P(B) + P(C) if A,B,C are disjoint events
The probability that even A, B or C occur is equal to the sum of their
probabilities if the events are disjoint, if they are not disjoint, use rule #3