What is Probability?
Alg2 CC
Name:
Probability is a branch of mathematics in which a numerical value is used to express the likelihood of an event
or outcome. An outcome is the result of some activity. Probability has to do with certainty, uncertainty, and
prediction - that is, with chance. The probability of an event is the chance that it will occur, often expressed as
a ratio of a specific event to all possible events. All the possible results, or outcomes, are called the sample
space.
Experiment - Some process that occurs with well-defined outcomes.
Outcome – A result from a single trial of the experiment.
Event – A collection of one or more outcomes.
Sample Space – A collection of all of the outcomes of an experiment.
1) List the sample space for each experiment.
Experiment
Rolling a die once
Tossing a coin three times
Spinning a spinner once.
Rolling a pair of dice
Choosing an outfit consisting of a blouse, a
skirt, and shoes from a green blouse, a red
blouse, a black skirt, and a pair of sneakers
and a pair of sandals.
Sample Space
2) An experiment is run whereby a die is rolled.
a) What is the probability of landing on an odd number?
b) What is the event?
c) What outcomes fall into the event?
3) Let’s say our experiment now involves rolling a die twice.
a) How many possible outcomes make up the sample space?
b) What is the probability of getting exactly two 6’s?
c) What is the probability of getting exactly one 6?
Regents Review:
A)
B)