3.2 Fundamentals of Probability

3.1 Overview

3.2    Terms

    Experiment

    Sample Space

    Simple Event

    Event

    Probability of Event A    if equally likely
 
 

Round off Rule for Probability    Use 3 significant digits as decimal or fraction
 

Two Methods of Finding Probability

    Method 1 -  Relative Frequency Approximation
 
                    -  s = number of times A occurred
 
                    -  n = number of times event was performed

                    -  Law of Large Numbers - pg. 124
 
 

         #8    Versus   #14
 
 
 
 
 
 

        #18
 
 
 
 
 

         #22
 
 
 
 

    Method 2 - Classical Approach -  n simple, equality likely events
 
 
 
                         -   s = number of ways A can occur
 
                    -  n = number of different simple events
 
 

        #4
 
 
 
 
 

        #26
 
 
 
 

       Multiple Choice Questions
 
 
 
 
 

Equally Likely -    Random Sample of n items
 
 
Probability Values Range from 0 to 1     

 
                Page 127 is excellent reference of probability

                Probability of Impossible Event = 0

                Probability of Certain Event  = 1
 
 
 

Examples

        Multiple Births    -  GGG, GGB, etc.
 
 
 
 

        Roll 2 die  -  Think Green & Red
 
 
 
 
Complementary Events  

          Family of 3 kids, probability of at least one boy
 
 

       #24
 
 
 

Odds        n = a + b    where a  is the number of ways A occurs, and
 
                                    b  is number of ways A doesn't occur
 
a : b    or  are odds in Favor of A
 
 b : a     or  are odds against A        
                                      

               

       #28
 
 

       #30