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