SOLUTION: It is known that one out of every five tax returns will contain errors and are classed as faulty. Calculate the probability that in a sample of five tax returns (i) none are faulty

Algebra ->  Probability-and-statistics -> SOLUTION: It is known that one out of every five tax returns will contain errors and are classed as faulty. Calculate the probability that in a sample of five tax returns (i) none are faulty      Log On


   

Question 822162: It is known that one out of every five tax returns will contain errors and are classed as faulty. Calculate the probability that in a sample of five tax returns (i) none are faulty (ii) at least one is faulty
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
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
-----
Calculate the probability that in a sample of five tax returns
(i) none are faulty
P(x = 0) = (4/5)^5 = 0.3277
--------------------------
(ii) at least one is faulty
P(x >=1) = 1 - P(x = 0) = 1 - (4/5)^5 = 0.6723
=======================
Cheers,
Stan H.
=======================