Probability

Probability

1. chance

2. Likelihood scale - likely, very likely, unlikely, very unlikely, certain, impossible, evens or 50/50

3. Probability Scale - starts at 0 (impossible) and ends at 1 (certain)

4. Relative frequency = number of desired outcomes/total number

5. Expected frequency = relative frequency x no of trials

6. Fairness - all outcomes are equally likely

7. Biased - not all outcomes are equally likely

8. Probability of an event not happening = 1 - probability that it does happen

9. Tree diagrams

   • Two way tables

10. Fundamental principle of counting: if one event has m outcomes and a second event has n outcomes then the total number of outcomes is m x n