In an experiment with $15$ observations on $x$,we have $\sum x^2 = 2830$ and $\sum x = 170$. One observation that was $20$ was found to be wrong and was replaced by the correct value $30$. The corrected variance is:

  • A
    $177.33$
  • B
    $188.66$
  • C
    $80.33$
  • D
    $78$

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