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Find mean, variance, and standard deviation for a Binomial distribution

Find mean, variance, and standard deviation for a Binomial distribution-example-1
User Tuxmentat
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1 Answer

11 votes
11 votes

The mean, variance, and standard deviation of a binomial distribution with parameters n and p are:


\begin{gathered} \operatorname{mean}=n\cdot p \\ \text{variance = n}\cdot p\cdot(1-p) \\ \text{ Standard deviation =}\sqrt[]{n\cdot p\cdot(1-p)} \end{gathered}

So, replacing the values of n and p, we get:


\begin{gathered} \operatorname{mean}=128\cdot0.49=62.72 \\ \text{variance}=128\cdot0.49\cdot(1-0.49)=31.9872 \\ \text{ standard deviation = }\sqrt[]{31.9872}=5.6557 \end{gathered}

Answer: mean = 62.72

variance = 31.9872

standard deviation = 5.6557

User Mayur Kharche
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3.0k points