Measurement of Dispersion
Question
Q1.
Which measurement of dispersion is appropriate for open end data .
Solution.
Quartile deviation
Solution
Q2.
Which is the best measurement of dispersion.
Standard Deviation
Solution
Q3.
Standard deviation of the frequency distribution is 9. When each observation is increased by 6 then new S.D. is
Solution.
9
Note ; Standard deviation is a measurement of dispersion.Measurement of dispersion has no impact of change of origin
.
Solution
Q4.
For a moderately skewed distribution Quartile deviation and mean deviation are related by.
(a) QD = 5/6 MD (b) QD = MD
(c) QD = 3/2 MD (d) QD = 2/3 MD
Solution.
(a) QD = 5/6 MD
Solution
Q5.
If V(x) = 9 then V(5 - 2x) =
Solution.
36
Note : V(ax) = a2 V(x)
Solution
Q6.
Mean deviation can be calculated from mean,median and mode , the value of M.D. will be minimum when it is calculated from ________ .
Solution.
Median
Solution
Q7.
The standard deviation of first six natural numbers is .
Solution.
√(35/12)
Note : S.D. of first n natural numbers is √(n2-1/12)
Solution
Q8.
The quartile deviation of data is 10 , if all the values of the data are multiplied by 10.Then what will be the new quartile
deviation.
Solution.
100
Note : Quartile deviation is a measurement of dispersion which has impact of change of scale .
Solution
Q9.
Write the formula of semi-interquartile range .
(a) (Q3 - Q1)/2 (b) (Q3 + Q1)/2
(c) (Q3)/2 (d) Q1/2
Solution.
(Q3 - Q1)/2
Solution
Q10.
If coefficient of variation is less then the data is
(a) more consistent (b) less consistent (c) none of these
Solution.
(a) more consistent
Solution
