**711. Mean deviation computed from a set of data is always:**

A.Negative

B.Equal to standard deviation

C.More than standard deviation**D.Less than standard deviation**

**712. Which measure of dispersion has a different unit other than the unit of measurement of values:**

A.Range

B.Standard deviation**C.Variance**

D.Mean deviation

**713. The positive square root of the mean of the squares of the cleviations of observations from their mean is called:**

A.Variance

B.Range**C.Standard deviation**

D.Coefficient of variation

**714. S.D(X) = 6 and S.D(Y) = 8. If X and Yare independent random variables, then S.D(X-Y) is:**

A.2**B.10**

C.14

D.100

**715. The ratio of the standard deviation to the arithmetic mean expressed as a percentage is called:**

A.Coefficient of standard deviation

B.Coefficient of skewness

C.Coefficient of kurtosis**D.Coefficient of variation**

**716. To compare the variation of two or more than two series, we use**

A.Combined standard deviation

B.Corrected standard deviation**C.Coefficient of variation**

D.Coefficient of skewness

**717. If standard deviation of the values 2, 4, 6, 8 is 2.236, then standard deviation of the values 4, 8,12, 16 is:**

A.0**B.4.472**

C.4.236

D.2.236

**718. The moments about mean are called:**

A.Raw moments**B.Central moments**

C.Moments about origin

D.All of the above

**719. Moment ratios β1 and β2 are:**

A.Independent of origin and scale of measurement

B.Expressed in original unit of the data**C.Unit less quantities**

D.Both (a) and (c)

**720. If the third moment about mean is zero, then the distribution is:**

A.Positively skewed

B.Negatively skewed**C.Symmetrical**

D.Mesokurtic