<PRE><B>Question 394210</B>
Find probability if a coin is tossed 5 time
P(0 tails) = P(5 heads) = (1/2)^5 = 1/32
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P(exactly 1 tail) = 5C1(1/2)(1/2)^4 = 5(1/32) = 5/32
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P(at most 2 tails) = P(0,or 1, or 2 tails) = (1/32) + (5/32) + 5C2(1/2)^5
= 6/32 + 10/32 = 16/32 = 1/2
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P(at least 4 tails) = P(4 or 5 tails) = 5C4(1/2)^5 + 5C5(1/2)^5 
= 5/32 + 1/32 = 6/32 = 3/16
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Cheers,
Stan H.
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