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Let us take Bernoulli trial of tossing a coin. If there are 70 independent trials, and finding a head is a success, what will be the variance?

Let us take Bernoulli trial of tossing a coin. If there are 70 independent trials, and finding a head is a success, what will be the variance? Correct Answer 17.5

Variance of the binomial distribution, σ2=np(1-p) For tossing a coin and finding a head, p = 0.5, which gives variance = 17.5.

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