elem stats Probability and Counting Rules

(quantify) chance of an event occurring

Probability:

• experiment with an outcome

• consists of a set of outcomes of a probability experiment.

event

• is a chance process that leads to well-defined results called outcomes. 

A probability experiment

the result of a single trial of a probability experiment.

outcome

• the set of all possible outcomes of a probability experiment. 

A sample space

experiment vs sample space

Sample spaces and probability 

3 basic interpretations of probability

1. classical probability

2. empirical probability

3. Subjective probability

classical probability

1.  [ random, all things have chance to occur]- can be measured but only by percentage or counting 

   1. Assumes that Chances are equally likely 

   2. Theoretical (only the likelihood); dont have to actually do it just solve 

Empirical probability

1. [ it can be counted] 

   1. Relies on actual experience to determine likelihood of outcomes

   2. Actual event 

Subjective Probability

1.  [ own opinion based on experience(can also be based on medical data)] - not really accurate 

Based on educated guesses or estimates employing opinions and inexact

Rounding rule

• 3 decimal places, round off