Question 1203339
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Topic : Discrete Random Variable (Geometric Distribution)
In a particular country, 18% of adults wear contact lenses. 
Adults are randomly selected and interviewed once at a time. 
Find the probability that the first adult who wears contact lenses is:
(a) One of the first 15 interviewed
(b) Not one of the first nine interviewed
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<pre>
(a) It is a typical binomial distribution probability.
    The number of trials is 15; the number of success is 1 (one);
    the probability of success at each individual trial is 0.18.


    You may use a standard probability formula

       P = {{{C[15]^1*0.18*(1-0.18)^17}}} = {{{15*0.18*0.82^17}}} = 0.0925  (rounded).    <U>ANSWER</U>



(b) The  <U>ANSWER</U>  is P = {{{(1-0.18)^9}}} = {{{0.82^9}}} = 0.1676  (rounded).   
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Solved.