Department of Pre-University Education, KarnatakaPUC Karnataka Science Class 12
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# If in a Binomial Distribution Mean is 5 and Variance is 4, Write the Number of Trials. - Mathematics

#### Question

If in a binomial distribution mean is 5 and variance is 4, write the number of trials.

#### Solution

$\text{ Mean = 5 and Variance } = 4$
$\Rightarrow \text{ np = 5 and npq } = 4$
$\Rightarrow q = 0 . 8$
$\Rightarrow p = 1 - q = 0 . 2$
& np = n(0 . 2) = 5 (given)
$\Rightarrow n = \frac{5}{0 . 2} = 25$

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