If the variance of observations ${x_1},\,{x_2},\,......{x_n}$ is ${\sigma ^2}$, then the variance of $a{x_1},\,a{x_2}.......,\,a{x_n}$, $\alpha \ne 0$ is

  • A

    ${\sigma ^2}$

  • B

    $a\,{\sigma ^2}$

  • C

    ${a^2}{\sigma ^2}$

  • D

    $\frac{{{\sigma ^2}}}{{{a^2}}}$

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