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[[Category:ECE302Spring2013Boutin]] [[Category:ECE]] [[Category:ECE302]] [[Category:probability]] [[Category|problem solving]]
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[[Category:ECE302Spring2013Boutin]] [[Category:ECE]] [[Category:ECE302]] [[Category:probability]] [[Category:problem solving]]
  
 
[[Category:conditional probability]]
 
[[Category:conditional probability]]
  
Q:
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==Problem Involving Conditional Probability==
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Question:
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If there are 2 white balls and 4 red balls in box 1, and 5 white balls and 3red balls in box 2. Now randomly take one ball from box 1 and put into box 2. Then take one ball from box 2.
 
If there are 2 white balls and 4 red balls in box 1, and 5 white balls and 3red balls in box 2. Now randomly take one ball from box 1 and put into box 2. Then take one ball from box 2.
(1) If under the condition that the ball being taken from box1 is red, what is the possibility that the ball that's taken from box 2 is also red?
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# If under the condition that the ball being taken from box1 is red, what is the possibility that the ball that's taken from box 2 is also red?
(2)What's the possibility that the ball that's taken from box 2 is red?
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# What's the possibility that the ball that's taken from box 2 is red?
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Answer:
  
A:
 
 
(1)Assume event A is the ball that's taken from box 2 is red; and event B is the ball that's taken from box 1 is red.
 
(1)Assume event A is the ball that's taken from box 2 is red; and event B is the ball that's taken from box 1 is red.
  
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       =(4/9)*(2/3) + (1/3)*(1/3)  
 
       =(4/9)*(2/3) + (1/3)*(1/3)  
 
       =11/27
 
       =11/27
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==Comments/discussion==
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*Write comment here
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**answer here
  
 
[[Bonus_point_1_ECE302_Spring2012_Boutin|Back to first bonus point opportunity, ECE302 Spring 2013]]
 
[[Bonus_point_1_ECE302_Spring2012_Boutin|Back to first bonus point opportunity, ECE302 Spring 2013]]

Latest revision as of 11:47, 28 January 2013


Problem Involving Conditional Probability

Question:

If there are 2 white balls and 4 red balls in box 1, and 5 white balls and 3red balls in box 2. Now randomly take one ball from box 1 and put into box 2. Then take one ball from box 2.

  1. If under the condition that the ball being taken from box1 is red, what is the possibility that the ball that's taken from box 2 is also red?
  2. What's the possibility that the ball that's taken from box 2 is red?

Answer:

(1)Assume event A is the ball that's taken from box 2 is red; and event B is the ball that's taken from box 1 is red.

P(B) = 4/(2+4) = 2/3

P(A|B) =P(A_AND_B)/P(B)

         = (2/3)*(4/9)/(2/3)
         =4/9

(2)

P(B) = 4/(2+4) = 2/3

P(NOT_B) = 1 - 2/3 = 1/3

P(A) = P(A_AND_B) + P(A_AND_NOTB)

      = P(A|B)*P(B)  + P(A|NOT_B)*P(NOT_B)
      =(4/9)*(2/3) + (1/3)*(1/3) 
      =11/27

Comments/discussion

  • Write comment here
    • answer here

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Basic linear algebra uncovers and clarifies very important geometry and algebra.

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