The arithmetic mean of the numerical values of the deviations of items from some average value is called the
Range
Quartile deviation
Mean deviation
Standard deviation
Out of Range, Quartile Deviation, Mean Deviation and Standard Deviation, which one suits the best in terms of following Parameters:
(i) Ease of Calculation
(ii) Based on all the items
(iii) Less effect of Extreme Items
State with reason whether the following statements are True or False:
(i) Sum of square of the deviations of items from their arithmetic mean is the maximum.
(ii) Standard Deviation is based on all values.
(iii) For a given set of observations, standard deviation is always more than mean deviation from mean.