731. Which of the following statements is correct?
A.The standard deviation of a constant is equal to unity
B.The sum of absolute deviations is minimum if these deviations are taken from the mean.
C.The second moment about origin equals variance
D.The variance is positive quantity and is expressed in square of the units of the observations

732. In a set of observations the variance is 50. All the observations are increased by 100%. The variance of the increased observations will become:
A.50
B.200
C.100
D.No change

733. All odd order moments about mean in a symmetrical distribution are:
A.Positive
B.Negative
C.Zero
D.Three

734. The first three moments of a distribution about the mean X are 1, 4 and 0. The distribution is:
A.Symmetrical
B.Skewed to the left
C.Skewed to the right
D.Normal

735. For a positively skewed distribution, mean is always:
A.Less than the median
B.Less than the mode
C.Greater than the mode
D.Difficult to tell

736. Bowley’s coefficient of skewness lies between:
A.0 and 1
B.1 and +1
C.-1 and 0
D.-2 and +2

737. The second and fourth moments about mean are 4 and 48 respectively, then the distribution is:
A.Leptokurtic
B.Platykurtic
C.Mesokurtic or normal
D.Positively skewed

738. The measures used to calculate the variation present among the observations in the unit of the variable is called:
A.Relative measures of dispersion
B.Coefficient of skewness
C.Absolute measures of dispersion
D.Coefficient of variation

739. The measure of dispersion which uses only two observations is called:
A.Mean
B.Median
C.Range
D.Coefficient of variation

740. Half of the difference between upper and lower quartiles is called:
A.Interquartile range
B.Quartile deviation
C.Mean deviation
D.Standard deviation