Question 342847
If 4 factories in a group of 20 factories in a community are violating environmental regulations and 6 are randomly selected for inspection, what is the probability that none of the violators will be selected? 
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16 of the 20 factories are not violators.
P(not violator) = 16/20 = 4/5 = 0.8
P(violator) = 0.2
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Binomial Problem with n= 6 and p = 0.8
P(x=6 non-violators) = 6C6(0.8)^6(0.2)^0 = 0.8^6 = 0.2621
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Cheers,
Stan H.