Q12 of 99 Page 33

If X follows binomial distribution with parameters n = 5, p and P(X = 2) = 9 P(X = 3), then find the value of p.

Given:


n=5


p(x=2)=9p(x=3)


p=?


P(x=r)= nCr pr qn-r


P(x=1)= 5C1 p1 q4


= 5p q4


P(x=3)= 5C3 p3 q2


= 20 p3 q2


Put values in equation, we have:


5p q4= 9(20 p3 q2)


q2= 9(4 p2)


(1-p)2= 36p2


1+p2-2p= 36p2


35p2+2p-1=0



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