Basic Concepts of Probability
A. Bourhim
Syracuse University
MAT121, Spring 2015
A. Bourhim (Syracuse University)
Basic Concepts of Probability
MAT121, Spring 2015
1 / 14

Other details, examples and the
solution of the examples will be
presented in the class. Your
attendance is therefore required.
A. Bourhim (Syracuse University)
Basic Concepts of Probability
MAT121, Spring 2015
2 / 14

Rare Event Rule
If, under a given assumption, the probability of a particular observed event is
extremely small, we conclude that the assumption is probably not correct.
Definition
An
outcome
is the result of a single trial of an experiment.
An
event
is one or more outcomes of an experiment.
Any event which consists of a single outcome is called a
simple event
.
The
sample space
is the list of all outcomes.
A. Bourhim (Syracuse University)
Basic Concepts of Probability
MAT121, Spring 2015
3 / 14

Example
A single 6-sided die is rolled.
The possible outcomes of this experiment are: 1, 2, 3, 4, 5, 6.
Rolling a single number (like 1 or 2) is a simple event.
Rolling an even number is an event: 2, 4, 6.
Rolling an odd number is an event: 1, 3, 5.
Rolling a number large than 3 is an event: 4, 5, 6.
A. Bourhim (Syracuse University)
Basic Concepts of Probability
MAT121, Spring 2015
4 / 14

Notation
Events are denoted by
A
,
B
,
C
, ...
Probability is the measure of how likely
A
is, and is denoted by
P
(
A
)
.