A survey conducted revealed that four out of every twenty taxi drivers do not have a valid driving license. If 6 drivers are selected at random, calculate, correct to three decimal places, the probability that (a) exactly 2 ; (b) more than 3 ; (c) at least 5; have valid driving license.
Explanation
p(have valid license) = p = 0.8 p(no valid license) = q = 0.2. The binomial probability distribution is (a) p(2 have valid licenses) = = = (3 d.p) (b) p(more than 3 have valid licenses) = = = = (3 d.p) (c) p(at least 5 have valid licenses) = = = = .
