<PRE><B>Question 840200</B>
A biased coin is tossed. The probability of getting a head is 0.8 and the probability of getting a tail is 0.2. What is the probability of getting the 3rd head in the 13th throw? 
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The pattern has 13 coin tosses with 3rd head in 13 position.
Example of the pattern:: hhtttttttttth
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The two heads can be placed in 12C2 = (12*11)/(1*2) = 66 different ways
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Probability of each pattern is (1/2)^13
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Ans: 66(1/2)^13 = 0.0081
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Cheers,
Stan H.
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