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Independent Events

Date: 08/07/98 at 07:25:23
From: DiCicco's
Subject: Re: Linear equations and probabilities

Hi Dr. Math, 

Thank you very much for your last answer. I have another question. 

Let A and B be two events where P(A) = 0.6, P(B) = 0.2, and 
P(A intersect B) = 0.12. Are the events A and B independent? Why?

If you can tell me how and why of this question I would truly 
appreciate it.


Date: 08/07/98 at 12:40:40
From: Doctor Anthony
Subject: Re: Linear equations and probabilities

The test for independence of two events A and B is as follows:

   If  P(A and B) = P(A) x P(B)  then A and B are independent.

In your example we have:

   P(A and B) = 0.12
   P(A) = 0.6
   P(B) = 0.2

So P(A) x P(B) = 0.6 x 0.2 = 0.12 = P(A and B)

and therefore A and B are independent.

- Doctor Anthony, The Math Forum
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Associated Topics:
High School Probability

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