The variance of 20 observations is 5. If each observation is multiplied by 2 find the variance of the resulting observations.

Answer

Variance is `20`

Explanation

`Rightarrow Let the observations be {x}_{1}, {x}_{2}, {x}_{3}, ldots, {x}_{20} and Rightarrow{{x}} `be their mean.


`Rightarrow Variance =5 and {n}=20`.


` Rightarrow {V} Variance ``=frac{1}{{n}} sum({x}_{{i}}-Rightarrow{{x}})^{2}`

` 5 =frac{1}{20}`

`sum({x}_{{i}}-Rightarrow{{x}})^{2}}`



`therefore sum(x_{i}-bar{x})^{2}=100` —----> (i)



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