Chapter 7
complement of event
The complement of event A consists of all outcomes that are NOT in A.
Addition Rule of Probability
P(A or B) = P(A) + P(B) - P(AB) *OR, EITHER*
Intersection of Events
The intersection of events is given by the outcomes that are common to two (or more) events.
Union of two events * OR*
The union of events A and B is the event containing all sample points that are in A or B or both Both A and B
relative frequency approach
expresses the probability of an outcome as the relative frequency of its occurrence based on past experience
Classical Approach
assigning equal probabilities to all the simple events
subjective approach
assigns probability to an event based on personal judgment
Three Approaches to Assigning Probabilities
classical, relative frequency, subjective
mutually exclusive events
events that cannot happen at the same time
intersection
the event that occurs when two or more other events occur
Joint Probability
the probability of the intersection of two events
Conditional Probability *GIVEN*
the probability that one event happens given that another event is already known to have happened
multiplication rule
the rule that allows us to calculate the probability of the intersection of two events;
Probability of an Event
the sum of the probabilities of the simple events that constitute the event.
event
a set of one or more simple events
three rules that enable us to calculate the probability of more complex events from the probability of simpler events
complement, multiplication rule, Addition Rule
marginal probabilities
computed by adding across rows or down columns, are so named because they are calculated in the margins of the table.