


Description 



Certain Event: An event with a probability of 1. 
Note that an event that cannot possibly happen has a
probability of zero. If there is a chance that an event will happen, then, its
probability is between zero and 1.
Examples of Events that are Certain:
 If it is Thursday, the probability that
tomorrow is Friday is certain, and therefore the probability is 1.
 If you are sixteen, the probability of you turning seventeen
on your next birthday is 1. This is a certain event.
Examples of Events That Are Not Certain:
 The probability that tomorrow is Friday if today is Monday is
0.
 The probability that a coin you toss will land on tails is .50.
 The probability that the groundhog will see its shadow on Groundhog Day.


