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CUET · MATHS · PYQ PAPER 2023

In a binomial distribution, the probability of getting a success is \(\frac{1}{3}\) and the standard deviation is 2 . Then its mean is :

  1. A 12
  2. B 8
  3. C 24
  4. D 6
Verified Solution

Answer & Solution

Correct Answer

(D) 6

Step-by-step Solution

Detailed explanation

\(\sigma^2 = np(1-p)\) \(2^2 = n \cdot \frac{1}{3} \cdot (1-\frac{1}{3})\) \(4 = n \cdot \frac{1}{3} \cdot \frac{2}{3} \Rightarrow 4 = \frac{2n}{9}\) \(n = \frac{4 \cdot 9}{2} = 18\) \(\text{Mean } \mu = np\) \(\mu = 18 \cdot \frac{1}{3} = 6\)