Unit 3 Section 4 Simple Probability.notebook
Simple Probability
Unit 3
December 18, 2014
Unit 3 Section 4 Simple Probability.notebook
December 18, 2014
Vocabulary
Probability: the chance that a given event will occur.
Some areas where probability is used are sports,
weather, politics, and agriculture. Also when you
guess answers on a test or play games involving di or
enter a sweepstakes.
Unit 3 Section 4 Simple Probability.notebook
December 18, 2014
Event: Outcome or combination of outcomes
Outcomes: Possible results. Outcomes on a di are (1, 2, 3, 4, 5, 6)
Probability Formula:
Favorable Outcomes: the outcome that you are calculating the likelihood
of its occurrence.
Unit 3 Section 4 Simple Probability.notebook
December 18, 2014
Example 1: Find each probability. Use the spinner.
a) P(2)
b) P(blue)
6
1
c) P(10)
2
5
d) P(blue,red, green)
4
3
Unit 3 Section 4 Simple Probability.notebook
December 18, 2014
Theoretical Probability: the calculation using the probability formula
that a favorable outcome will occur.
All Probability Ranges between 0 to 1. The probability of an
impossible event is always 0 and the probability of a certain event is
always 1.
In your own words describe the different values of probability.
Experimental Probability: what actually does happen in an experiment.
Unit 3 Section 4 Simple Probability.notebook
December 18, 2014
Example 2: The hair color of students in class are as follows : 8
brown, 10 black, 2 red, and 3 blonde. If the teacher calls on one
student at random, what is the probability of calling on a student with
brown hair?
What is the probability that the teacher does not choose a student
with black hair?
Example 3: In a batch of 350 calculators, 7 were found to be defective.
What is the probability that a calculator chosen at random will be
defective? Write the probability as a fraction and a percent. Round to
the nearest tenth of a percent if necessary.
Unit 3 Section 4 Simple Probability.notebook
December 18, 2014
Example 4: Suppose two 1-6 number cubes are rolled. Find the
probability of each outcome. (Hint: Use the table below as your sample
space.)
a) P(2 or 6)
b) P(both even)
c) P(sum less than 7)
d) P(odd product)
(1, 1) (2, 1) (3, 1) (4, 1) (5, 1) (6, 1)
(1, 2) (2, 2) (3, 2) (4, 2) (5, 2) (6, 2)
(1, 3) (2, 3) (3, 3) (4, 3) (5, 3) (6, 3)
(1, 4) (2, 4) (3, 4) (4, 4) (5, 4) (6, 4)
(1, 5) (2, 5) (3, 5) (4, 5) (5, 5) (6, 5)
(1, 6) (2, 6) (3, 6) (4, 6) (5, 6) (6, 6)