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**pumbaa213** The variable X has a binomial distribution with n=20 and probability of success p, where p<0.1.

(i) write down an expression, in terms of p, for P(X=2).

(ii) show that p=0.05, correct to 2 decimal places if given that P(X>=1) [x is larger or equals to 1)=0.641541

Im having problems with part (ii)

This is my attempt at it: If its rubbish, just ignore it! x.x

P(X>=1) = 0.641541

P(X>=1) can be written as 1-P(X=0)

Hence,

1-P(X=0) =0.641541

Given that n=20

20C0 x p^0 x (1-p)^20 = 0.641541

1 x (1-p)^20 = 0.641541

p^20=0.641541