Probability What are your Chances?

Warm Up Write each fraction in simplest form

Overview  Probability is the study of random events, written P(event). Event: Any possible outcome of an experiment, such as getting a 2 from rolling a number cube. Outcome: a possible result of an experiment.

Overview  Probability, can be written as a part to whole ratio, percent or decimal.

Overview  The probability, or chance, that an event will happen can be described by a number between 0 and 1:  A probability of 0, or 0%, means the event has no chance of happening.  A probability of 1/2, or 50%, means the event is just as likely to happen as not to happen.  A probability of 1, or 100%, means the event is certain to happen

Overview You can represent the probability of an event by marking it on a number line like this one

A. The sun will rise tomorrow. B. tomorrow will be Friday C. tossing heads on a coin. D. Drawing lucky seven in a deck of 52 cards. E. Not rolling a 6 on a number cube. Certain Impossible As likely as not/equally likely Unlikely Likely

Experimental Probability  The chances of something happening, based on repeated testing and observing results. It is the ratio of the number of times an event occurred to the number of times tested.  The more trials you have, the more accurate the estimate is likely to be.

EXPERIMENTAL PROBABILITY P(event)  number of times an event occurs total number of trials Trial: Each repetition or observation of an experiment.

Getting Started with Probability To get an overview of probability, click on the spinner and select the Introduction to Probability lesson. Make sure you are in slide show view then CLICK on the spinner

Describe a Situation 1.Describe a situation where the probability is ½. 2.Describe a situation where the probability is ¼. 3.Describe a situation where the probability is 5/9.

Make your own problem Here is a chance for you to design your own probability experiment.  What will you use? (dice, coins, colors)  What are all of the possible outcomes of the event?  Assign probabilities to the events using fractions or percents.  Make predictions.

Coin Toss Optional Create a worksheet that looks like this. Toss a coin 25 times. Total the number of heads and tails. What percent was heads? Tails? Toss a coin another 25 times. Total the number of heads and tails for this trial. Add both trials together. Is there a difference in the percentage when you calculate 50 tosses versus 25 tosses?

Group Activity Coin Toss Optional Part 1 Using 1 die or pieces of paper with the numbers 1-6. Conduct a trial by rolling the die 100 times (or picking a piece of paper and returning it to the pile ). What do you think is the probability of picking a 1. How many times did you roll or pick 1, 2, 3, 4, 5, 6? What is the percentage for each number? Part 2 Combine your 100 rolls/picks with the 3 others in your group. What is the percentage for each number out of the now 400 rolls/picks? Submit a spreadsheet with this information, as well as a graph.

The Cereal Problem: Optional Use a computer simulation to find out how many boxes of cereal one would need to buy to get all 6 prizes. Make sure you set the number of prizes to 6. Record the results of at least 10 trials to get an average of the trials. Make sure you are in slide show view then CLICK on the Cereal box