Question 1208361
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It is known that a certain drug causes side effects in 12
% of patients. If we consider a random sampling of
12 patients, what is the probability less than two have the side effect?
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Binomial distribution.

The number of trials 12.

The probability of success in each individual trial is p = 0.12.

The number of successive trials is less than 2, i.e. 0 or 1.


Standard formula

    P = {{{C[12]^0*p^0*(1-p)^12 + C[12]^1*p^1*(1-p)^11}}} = {{{1*0.12^0*(1-0.12)^12 + 12*0.12^1*(1-0.12)^11}}} = 0.5686 (rounded).
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Solved.