Week 2 - Probability I Flashcards
What is the Frequentist idea of probability
The probability that an event happens is the number of times that event occurs, as a percentage of the total number of times it could have happened
What is an Experiment
An activity which has a range of possible outcomes
What is a Trial
A single performance of the experiment
What is the Sample space
All possible outcomes of the experiment
What is an Event
A combination of outcomes
What is Mutually exclusive
Only one outcome can arise from a single trial
What are the rules for Probabilities (x3)
- A probability always lies between 0 and
- The sum of the probabilities of all outcomes in the sample space must equal 1
- The probability of an outcome not occurring must equal 1 minus the probability of an outcome occurring
- not A is called the complement of A
Describe Impossible and Certain events
- If Pr(A) = 0 then event A will never happen (impossible)
- if Pr(A) = 1 then event A will always happen (certainty)
What are Compound events
Combines events with joint probability, ‘and’ and ‘or’
What are Disjoint events
Joint probabilities of compound events are 0
What are Non-disjoint events
Events that can both occur at the same time, their set of outcomes in the sample space overlap
What is the Intersection of 2 events
Where event A AND event B occur
What is the Union of 2 events
Where event A OR event B occurs OR both events occur
