Probability vs Odds

January 30, 2014

Uh oh, I just realized there is a difference between Probability and Odds! Let's recap probability first:

P(A)=The Number Of Ways Event A Can Occur

        The Total Number of Possible Outcomes

The definition of odds: The odds of an event occurring is the ratio of the number of ways the event can occur(successes) to the number of ways the event cannot occur(failures). For the odds of an event occurring(odds in favor) it can be written as successess:failures or:

The Number of Ways Event A Can Occur(successes)

  The Number of Ways Event A Cannot Occur(failures)

Now if we're talking about the odds of an event not occuring(failures) then it is written as failures:successes or:

The Number of Ways Event A Cannot Occur(failures)

The Number of Ways Event A Can Occur(successes)

 Let's go back to my initial post about choosing sick(green) fish or healthy(not green) fish. Looking back, 10 of our 48 fish were sick and 38 were not . The odds then of choosing a sick fish is 10:38, ten times you will choose a sick fish and 38 times you will choose a healthy fish. Pout away Sheldon!