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A fair coin is flipped 7 times. What is the probability that at least 5 of the flips come up heads?

 

this is awesomeee. too lazy to login

 Apr 14, 2016
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The sum of these probabilities gives us the answer

 

P(5 heads)  = C(7,5) * (.5)^5 * (.5)^2  +

P(6 heads) = C(7,6) * (.5)^6 * (.5)^1 +

P(7 heads)  = (.5)^7

 

=  29 / 128     =  about 22.66%

 

 

 

cool cool cool

 Apr 14, 2016

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