Statistics Chapter 4
Sample space
a complete roster or listing of all elementary events for an experiment
Experiment
a process that produces outcomes
complement
all the elementary events of an experiment not in X comprise its complement
Subjective method
based on the feelings or insights of the person determining the probability
collectively exhaustive events
contains all possible elementary events for an experiment
Intersection
contains the elements common to both sets
marginal probability
denoted P(E), where E is some event. computed by dividing some subtotal by the whole
joint probability table
displays the intersection (joint) probabilities along with the marginal probabilities of a given problem
Elementary events
events that cannot be decomposed or broken down into other events
mn counting rule
for an operation that can be done m ways and a second operation that can be done n ways, the two operations then can occur, in order, in mn ways. this rule can be extended to cases with three or more operations
Union
formed by combining elements of from each of the sets
independent events
if the occurrence or nonoccurrence of on of the events does not affect the occurrence or nonoccurrence of the other event
conditional probability
is denoted P(E1/E2). the probability that E1 will occur given that E2 is known to have occurred
union probability
is denoted P(E1UE2), where E1 and E2 are two events. it is the probability that E1 will occur or E2 will occur or that both E1 and E2 will occur
combinations
sampling n items from a population of size n without replacement
joint probability
the intersection of two events. denoted as P(E1nE2)
complement of a union
the probability of a union of two events X and Y represents the probability that the outcome is either X or it is Y or it is both X and Y
Relative frequency of occurrence method
the probability of an event occurring is equal to the number of times the event has occurred in the past divided by the total number of opportunities for the event to have occurred
Set notation
the use of braces to group numbers, is used as a symbolic tool for unions and intersections
mutually exclusive events
two or more events if the occurrence of one event precludes the occurrence of the other event(s)
Classical method of assigning probabilities
when probabilities are assigned based on laws and rules