Question 131110
A medication is 75% effective against a bacterial infection. 
P(effective) = 0.75 ; P(not effective) = 0.25
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Find the probability that if 12 people take the medication, at least one person's infection will not improve:
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P(at least one not effective) = 1 - P(none are not effective)
= 1- P(all are effective) = 1 - (0.75)^12 = 0.968...
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Cheers,
Stan H.