Question

The correct relation between variance and standard deviation (S.D) of a variable X is _______.

• A. S.D = Var
• B. $S.D=\left[Var\right(X{)}^{\frac{1}{2}}]$
• C. $S.D=\left[Var\right(x){]}^2$
• D. None of the above

Answer 1

The correct option is B $S.D=\left[Var\right(X{)}^{\frac{1}{2}}]$

Standard deviation is the square root of the arithmetic mean of the squares of the deviations measured from the arithmetic mean of the data.

Variance is the mean of the squares of the deviations from the mean.

Standard deviation is the square root of variance or variance is the square of standard deviation.

S.D = {Var(X)}^1/2

or

Var(X) = (S.D)²