The variance of the first $n$ natural numbers is

  • A

    $\frac{{{n^2} - 1}}{{12}}$

  • B

    $\frac{{{n^2} - 1}}{6}$

  • C

    $\frac{{{n^2} + 1}}{6}$

  • D

    $\frac{{{n^2} + 1}}{{12}}$

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Let $\mathrm{n}$ be an odd natural number such that the variance of $1,2,3,4, \ldots, \mathrm{n}$ is $14 .$ Then $\mathrm{n}$ is equal to ..... .

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