A12­6TheoreticalAndExperimentalProb.notebook
January 07, 2013
Algebra 1
Ch.2 Notes Page 39
P39 2­6 Theoretical and Experimental Probability
Probability
What are the chances that some event will occur.
Probability (Event) = Favorable Outcomes
Total Outcomes
Example: Rolling an Even Number on a Number Cube
A12­6TheoreticalAndExperimentalProb.notebook
January 07, 2013
Theoretical Probability
What should happen if the experiment is done over and over again.
Favorable Outcomes
Total Outcomes
Tossing a coin.
(Should be 50% Heads and 50% Tails)
Experimental Probability
What does happen when you do the experiment.
Number Favorable Outcomes
Total Experiments
(If you toss the coin 100 times, you might get 60 heads and 40 tails.)
A12­6TheoreticalAndExperimentalProb.notebook
January 07, 2013
Complements
The Complement of an event is all of the outcomes not in the event.
The sum of the probabilities of an event and its complement is 1.
P(Not Event) = 1 ­ P(Event)
A Grand Prize is in one of 5 envelopes.
What is the chance of not picking the Grand Prize?
Odds
Odds compares favorable and unfavorable outcomes...
Odds in Favor = Number of Favorable
Number of Unfavorable
Odds Against = Number of Unfavorable
Number of Favorable
Find the odds in favor of the spinner landing on a number greater than or equal to 6.
A12­6TheoreticalAndExperimentalProb.notebook
January 07, 2013
Quality Control
A manufacturer has 8976 skateboards in its warehouse. If the probability that a skateboard has no defect is 99.2%, predict how many skateboards are likely to have no defects.
.992 x 8976 = 8904.2