This preview shows pages 1–2. Sign up to view the full content.
Definitions
•
Probability experiment
 An action, or trial,
through which specific results (counts,
measurements, or responses) are obtained.
•
Outcome
 The result of a single trial in a
probability experiment.
•
Sample Space
 The set of all possible
outcomes of a probability experiment.
•
Event
 Consists of one or more outcomes and
is a subset of the sample space.
•
Simple event
 An event that consists of a
single outcome (An event that consists of more
than one outcome is not a simple event).
•
Fundamental Counting Principle
 If one
event can occur in
m
ways and a second event
can occur in
n
ways, the number of ways the
two events can occur in sequence is
m*n
.
Can
be extended for any number of events occurring
in sequence.
•
Law of Large Numbers
 As an experiment is
repeated over and over, the empirical
probability of an event approaches the
theoretical (actual) probability of the event.
•
Subjective Probability
 Intuition, educated
guesses, and estimates.
•
Range of probabilities rule
 The probability of
an event
E
is between 0 and 1, inclusive.
0 ≤
P(E)
≤ 1
•
Complement of event
E (E')

The set of all
outcomes in a sample space that are not
included in event
E
.
Denoted
E
′ (
E
prime).
P
(
E
′) +
P
(
E
) = 1
•
Permutation
 An ordered arrangement of
objects. The number of different permutations of
n
distinct objects is
n
! (
n
factorial).
n
! =
n
∙(
n
–
1)∙(
n
– 2)∙(
n
– 3)∙ ∙ ∙3∙2 ∙1;
0! = 1
n
P
r
Ex
There are 15 dogs entered in a show.
How
many ways can first, second, and third place be
awarded?
N=15
R=3
15
P
3
15!/(133)!= 3,730 ways
•
Combination of
n
objects taken
r
at a time 
A
selection of
r
objects from a group of
n
objects
without regard to order
C
Ex
There are 13 students in a club.
How many
ways can four students be selected to attend a
conference?
N=13
R=4
13
C
4
13!/(134)!
(4!)= 715 ways
Formulas
Classical (theoretical) Probability 
Each
outcome in a sample space is equally likely.
Empirical (statistical) Probability 
Based on
observations obtained from probability experiments.
The relative frequency of an event.
4!
(4*3*2*1)=24
How many 4 letter TV call signs are possible, if
each sign must start with either a K or W?
1
st
letter=2 (K or W)
2
nd
letter=26
3
rd
letter=26
4
th
letter=26
2*26*26*26=35,152 possibilities.
Chapter 3 Review problems
On the basis of prior counts, a quality control officer says there
is a 0.05 probability that a randomly chosen part is defective.
Empirical probability
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
This is the end of the preview. Sign up
to
access the rest of the document.
 Fall '10
 Raney
 Probability

Click to edit the document details