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The random variable takes the values 1,2...

The random variable takes the values 1,2,3,…….m. If `P(X=n)=(1)/(m)` to each n, then the variance of X is

A

`((m +1)(2m +1))/(6)`

B

`(m^(2) -1)/(12)`

C

`(m+1)/(2)`

D

`(m^(2) +1)/(12)`

Text Solution

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The correct Answer is:
B
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