## 11.3a Probability Simulations

Sometimes we can figure out the probability of an event by looking at the choices in the sample space, for example, flipping a coin or rolling a six sided die.  Other times, we can't calculate the probabiliyt of something happening, like the percentage of making a free throw in basketball, or the probability of rolling a 6 on a weighted die.  At times like these, we can only estimate the probability be doing repeated experiments.  Today, you will do an activity that helps explore the differences between experimental and theoretical probability.

Resources

Assignment:

• Probability Simulation Worksheet

Things you should know after today:

• The difference between experimental and theoretical probability
• Why a probability simulation might be used

## 11.2 Outcomes of Independent Events

Sometimes you don't need to list all of the items in a sample space.  When we are finding probabilities, the denominator is the total # of outcomes; we can find this without listing out every single item in the sample space!

Things you should be able to do after today:

• find the number of outcomes from a series of independent events using multiplication
• determine when you can use multiplication to determine the number of outcomes

Resources

• Notes

Assignment:

• p423 #4-10

## 11.1 Determining Probabilities using a Tree Diagram or a Table

It is easy to calculate the probability of rolling a 6 on a six sided die, because we know how many possible outcomes there are, and how many of them are a 6. However, when you have 2 or more events (such as rolling 2 dice) it may be harder to determine the probability of something like "the 2 dice add up to 9 or more".  In these cases, it helps to list all of the possible outcomes and see how many of them are the ones that you want.

Today, we will be reviewing some basic ideas around probability, and then see how we can use tree diagrams or tables to help us determine a list of all of the possible outcomes.

Vocabulary you need to know:

• event
• outcome
• sample space
• indepenent events

Things you should be able to do after today:

• Determine the probability of an outcome using a sample space
• Determine a probabilty as a fraction, a decimal or a percent
• Determine a sample space for 2 or more events using a tree diagram
• Determine a sample space for 2 independent events using a table

Resources

• Notes

Assignment

• p416 #3-8, 10