In an experiment with $15$ observations on $x$, the following results were available $\sum {x^2} = 2830$, $\sum x = 170$. On observation that was $20$ was found to be wrong and was replaced by the correct value $30$. Then the corrected variance is..

  • [AIEEE 2003]
  • A

    $78$

  • B

    $188.66$

  • C

    $177.33$

  • D

    $8.33$

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  • [AIEEE 2012]