Expression of Simple Probability
 


Formula: number of "favorable" outcomes

divided by
 


number of possible outcomes


 


e.g. Survival Odds In Russian Roulette

(5 empty chambers and 1 bullet)

5 favorable / 6 possible outcomes

= 5/6 or 83.33% survival probability



Compound Probability

Independent Events


 
Dependent Events
 
Types of Probability

 
 

Classical


 
Relative Frequency
 
Subjective
 
 
 
Probability of Nuclear War

 
 
 
unthinkable
   
unavoidable

 
 
impossible
   
inevitable

 
 
denial
   
resignation

 
 
0%
   
100%

 
 
 
do
nothing
 
 
action
irrelevant
 

 
 
 
 
>0%
action
relevant
<100%