wk8 - Intro to Probability

sample

a collection of observations drawn from an underlying population

population

the entire collection of observations from which a sample can be drawn

Statistical inference

the bridge from features of samples to features of populations

outcome

the result of a random observation

Sample space

the collection of all possible outcomes

event

composed of one or more outcomes

Independent events

the probability that one event occurs does not change the probability of another event occurring

Mutually exclusive

when one cannot occur if the other does

Collectively exhaustive

if at least one of them must occur no matter what (rolling an odd or even number of a dice – covers the ENTIRE sample space)

What two ideas aid counting outcomes?

Permutations and combinations

permutation

a way of choosing k objects from n objects when one DOES care about the order in which one chooses the objects