Question

find the standard deviation of binomial random variable. A die is rolled 18 times and the number of fours that comes up is tallied

Answer 1

Complete Question

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Answer:

The standard deviation is
`\sigma =1.5811`

Explanation:

The sample size is n = 18

Generally the probability of getting a four in the toss of the fair die is mathematically represented as

`p = (1)/(6 )`

While the probability of not getting a four is

`q = 1 - p`

`q = 1 - (1)/(6)`

`q = (5)/(6)`

Now the standard deviation for the binomial random number is mathematically represented as

`\sigma = √(n * pq )`

substituting values

`\sigma = \sqrt{18 * (1)/(6)* (5)/(6) }`

`\sigma =1.5811`