13.1 Find Probability and

Odds

Vocabulary you should memorize:outcome: a possible result of an experimentevent: a specific outcome or collection of outcomessample space: the collection of all possible outcomesExample: When rolling a 6-sided die, you want to roll an odd number.

One outcome is to roll a 5. The event would consist of rolling a 1, 3, or 5. The sample space would be 1, 2, 3, 4, 5, and 6.

How to find a sample space:

One option is “brute force,” meaning to make a list and exhaust all options.

You flip 3 coins. What is the sample space?

Making a Tree Diagram:

You flip a coin and roll a number cube. How many outcomes are in the sample space? List all possible outcomes.

You flip 2 coins and roll a number cube. How many outcomes are in the sample space? List the possible outcomes.

probability: a number from 0 to 1 used to measure of the likelihood, or chance, that an event will occur.

-can be expressed as a decimal, fraction, or percent

Two different types of probability:

theoretical probability:

number of favorable outcomes

number of all possible outcomes

The “probability of A” can be written P(A).

experimental probability: based on repeated trials of an experiment.

number of successes

number of trials

odds: compare the number of favorable and unfavorable outcomes when all outcomes are equally likely.

odds in favor = # favorable outcomes

# unfavorable outcomes

odds against = #unfavorable outcomes

# favorable outcomes

Assuming that all colors are equally likely, find the odds for and the odds against landing on green.

Assignment:

pg. 846#3 – 16 all, 19, 20