Term

Definition
relative frequency with which that event can be expected to occur. 


Term

Definition
empirical probability of A = n times A occurred
number of trials
OR
algebra = P'(A) = n(A)/n 


Term
Theoretical (Expected Probability) 

Definition
theoretical prob A = n of times A occurs in sample space
n elements in sample space
OR
algebra = P(A) = n(A)
n(S) 


Term

Definition
results from a personal judgement 


Term
Properties of Probability Numbers (1) 

Definition
probability is always a numerical value between 1 and 0
0≤P(A)≤1 


Term
Properties of Probability Numbers (2) 

Definition
sum of the probabilities for all outcomes of an experiment is equal to exactly one
ΣP(A) = 1 for all outcomes 


Term
About Probability Numbers 

Definition
 probabiity represents a relative frequency
 P(A) = ratio of the number of times an event can be expected to happen
 P'(A) = ratio of the number of times an event did occur divided by the number of data
 numerator must be 0 or positive
 denominatior must be greater than zero
 probability will alway be a number between 0 and 1



Term

Definition
as the number of times an experiment is repeated increases, the ratio of the number of successful occurrences to the number of trials will tend to approach the theoretical probability of the outcome for an individual trial 


Term

Definition
the odds in favor of an event are a to b (a:b)
 ex) the odds against rain tomorrow are 1 to 4 (1:4)
 the probability of rain tomorrow is 4/(4+1)=4/5= 0.8
 probability that there will be no rain tomorrow is 1/(4+1) = 1/5 = 0.2



Term

Definition
relative frequency with which an event can be expected to occur under the condition that additional, preexisting information is known about some other event.
 P(AIB) = probability of event A occurring und the condition that event B is known to already exist



Term
Rules of Probability Compound event 

Definition
combinations of more than one simple event 


Term
Rules of Probability  Complementary Events 

Definition
complement of an event A (A), is the set of all sample points in the sample space that do not belong to A
 ex) complement of the event "success" is "failure"
Complement Rule
probability of A complement = oneprobability of A
P(A) = 1  P(A) 


Term

Definition
 Let A and B be two events defined in a sample space, S
 P(A or B) = P(A) + P(B)  P(A and B)



Term
General Multiplication Rule 

Definition
 A and B be two events defined in sample space, S
 P(A and B) = P(A) x P(BIA)


