2­6_Theoretical_Probability2010 web.notebook
December 07, 2010
2‐6 Theoretical &
Experimental Probability
Probability ‐ the chance that
something will happen
Theoretical Probability
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Objective ‐ Find out how likely it
is something will happen
of favorable outcomes
P(event) = number
total possible outcomes
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Dec 31 ­ 3:06 PM
Probability ‐ the chance that
something will happen
Ex) Find the probability of rolling the
number 5 with a single die.
Feb 23­7:03 PM
Ex) Find the probability of rolling an
even number with a single die.
Step 1: What are our possible outcomes?
Step 1: What are our possible outcomes?
Step 2: How many of those outcomes are favorable?
Step 2: How many of those outcomes are favorable?
Step 3: Write the probability of the event occurring.
Step 3: Write the probability of the event occurring.
Dec 31 ­ 3:06 PM
Dec 31 ­ 3:06 PM
Find the following probabilities when
rolling a single die.
The COMPLIMENT of an event
is the probability that the event will
NOT occur.
The sum of the probabilities of an event and its compliment is 1.
P(event) + P(not event) = 1
P(not 2) =
P(not 5) =
P(7) =
P(any # from 1 to 6) =
Feb 23­7:23 PM
Dec 31 ­ 3:06 PM
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2­6_Theoretical_Probability2010 web.notebook
December 07, 2010
Theoretical VS. Experimental probability
Theoretical Experimental P(red) =
P(red) =
P(orange) =
P(orange) =
P(not blue) =
P(not blue) =
Homework:
Probabilities Worksheet
Dec 31 ­ 3:06 PM
Dec 31 ­ 3:06 PM
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