For $20$ observations of variable $x$,if $\sum(x_{i}-2)=20$ and $\sum(x_{i}-2)^2=100$,then the standard deviation of variable $x$ is

  • A
    $2$
  • B
    $3$
  • C
    $4$
  • D
    $9$

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Similar Questions

The following table shows the information about marks obtained in Physics,Chemistry,Mathematics,and Biology by $100$ students in a class. Which subject shows the highest variability in marks?
PhysicsChemistryMathematicsBiology
Mean$20$$25$$23$$27$
$S$.$D$.$3$$2$$4$$5$

The variance of the ungrouped data $2, 12, 3, 11, 5, 10, 6, 7$ is

The mean of $5$ observations is $15$ and variance is $9$. If two observations having values $-5$ and $13$ are combined with these observations,then what will be the new variance?

The variance of the first $50$ even natural numbers is

The standard deviation of $7$ observations $1, 2, 3, 4, 5, 6, 7$ is:

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