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AP EAMCET · Maths · Probability

In a binomial distribution, the difference between the mean and standard deviation is 3 and the difference between their squares is 21 , then \(\mathrm{P}(x=1): \mathrm{P}(x=2)=\)

  1. A \(2: 1\)
  2. B \(1: 2\)
  3. C \(1: 3\)
  4. D \(3: 1\)
Verified Solution

Answer & Solution

Correct Answer

(C) \(1: 3\)

Step-by-step Solution

Detailed explanation

\(\text { Mean }=n p\) Standard deviation \(=\sqrt{2 p(1-p)}\) According to question, \(n p-\sqrt{n p(1-p)}=3\) \(\begin{aligned} & \Rightarrow n p-3=\sqrt{n p(1-p)} \\ & \Rightarrow(n p-3)^2=n p(1-p) ....(i) \end{aligned}\) And,…