The mean and standard deviation of $20$ observations were calculated as $10$ and $2.5$ respectively. It was found that by mistake one data value was taken as $25$ instead of $35 .$ If $\alpha$ and $\sqrt{\beta}$ are the mean and standard deviation respectively for correct data, then $(\alpha, \beta)$ is :

  • [JEE MAIN 2021]
  • A

    $(11,26)$

  • B

    $(10.5,25)$

  • C

    $(11,25)$

  • D

    $(10.5,26)$

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