Question 822162
 It is known that one out of every five tax returns will contain errors and are classed as faulty. ------
Binomial Problem with n = 5 and p(faulty) = 1/5
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Calculate the probability that in a sample of five tax returns 
(i) none are faulty 
P(x = 0) = (4/5)^5 = 0.3277
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(ii) at least one is faulty
P(x >=1) = 1 - P(x = 0) = 1 - (4/5)^5 = 0.6723
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Cheers,
Stan H.
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