Question 545422
One half of all U.S. households pay bills electronically. If seven U.S. households are randomly selected, what is the probability that exactly two pay bills electronically? 
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Binomial Problem with n = 7 and p(pay) = 1/2
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P(x = 2) = 7C2(1/2)^7 = 21/2^7 = 21/128
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Cheers,
Stan H.