<PRE><B>Question 580987</B>
A research team at a university conducted a binomial study showing that approximately 10% of all businessmen who wear ties wear them so tight that they actually reduce blood flow to the brain, diminishing cerebral functions. At the board meeting of the 15 businessmen, all of whom wear ties, what is the probability that 
a. exactly 6 ties are too tight?
binompdf(15,0.10,6) = 0.0019 
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b. at least one tie is too tight?
1 - P(none are too tight) = 1 - 0.9^15 = 0.7941
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c. at least 13 are not too tight?
1 - binomcdf(15,0.9,12) = 0.8159
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Cheers,
Stan H.
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