NOTE 1 (PROBABILITIES)* Probabilities are between zero and one, and represent the relative likelihood an event will happen if the same experiment is repeated identically many times. Sometimes we calculate probabilities by examining past history, sometimes we assume a theoretical model such as lottery balls are chosen fairly, and sometimes we use pure judgment.

Sometimes in the real world we use combinations of the relative frequency approach plus judgment. I would put weather forecasts in this category. Presumably the meteorologist makes an informed judgment based on what he or she knows about weather conditions, and is not just flipping a coin.

“One common mistake is to incorrectly assume that outcomes are equally likely just because we know nothing about the likelihood of each outcome.”

*QUESTION #1 – NEED 75 WORDS* What are your thoughts regarding probability?

*NOTE 2* Simulations as an alternative approach to finding probabilities. A simulation is a model of a procedure, rather than the actual procedure. An airplane pilot learns on a simulated airplane cockpit before actually taking off. Resusci Annie is a model of a training manikin to teach CPR. Is likely in 200 coin flips to get a run of 6 consecutive heads or 6 consecutive tails. In edition 11 the author used this activity and declared “This activity is more fun than human beings should be allowed to have.” I would not physically flip a coin 200 times and record the results.

*QUESTION #2* – NEED 75 WORDS* Can anyone see a potential use they might have for simulation, rather than actually collecting samples?

*NOTE 3* In some probability problems, the set of all possible outcomes is small enough that you can list them and use them to count the outcomes that interest you. But sometimes this is trickier than it sounds.


A family has two children. What is the probability that the children are a boy and a girl? *Please explain how you got it*


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