Probability

OverviewProbability is the study of random events.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.

For instance, the probability of a coin landing heads up is ½, or 50%, This means you would expect a coin to land “heads up”

half of the time.

Overview

The language of probability includes:•Experiment – a systematic investigation where the answer is unknown•Trial – one specific instance of an experiment•Outcome - the result of a single trial•Event – a selected outcome, such as getting an 11 from rolling two dice•Event Space/or Sample Space – the set of all possible outcomes of an experiment

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

Impossible 0 = 0%

Certain 1 = 100%

50 – 50 Chance½ , .5, 50%

Getting Started with Probability

To get an overview of probability, click on the spinner and select the Introduction to Probability lesson.

Read through the examples and take the quiz at the end.

Make sure you are in slide show view then CLICK on the spinner

Once you finish…

Complete Probability Worksheet