Page 204 - DSOC404_METHODOLOGY_OF_SOCIAL_RESEARCH_ENGLISH

Methodology of Social Research

note 27.6 Merits of Arithmetic Average or Mean
To find the mean everyone accepts the importance of arithmetic average because of its given below
features-
1. Arithmetic average is clearly defined and therefore, no one doubts it.
2. it is very easy to calculate arithmetic average and therefore, no high-level maths knowledge
is required for its calculation.
3. Because the technique of solving arithmetic average is very easy therefore more and more
people can take advantage of this. Because by knowing normal maths they all can easily
calculate mean.
4. there is no need to keep the series in a particular order for calculating arithmetic average. the
numbers can be as it is used to calculate the mean. Because in this only addition, subtraction,
etc. is used.
5. to calculate arithmetic average there is no need of the knowledge of every element in a series.
even if we know the value of the sum of the elements and the number of elements then we
can find out the mean. Similarly if we know the arithmetic average of two or more than two
series separately then we can find out the arithmetic average of the combined series.
6. in the arithmetic average, all small as well as big elements are given equal importance
and every element is counted only once. Neither any element is neglected nor given more
importance.
7. Arithmetic average is very useful for comparative study.

27.7 Demerits of Arithmetic Average

Besides above merits of arithmetic average there are some of its demerits also which are as follows:
a. it is also possible that arithmetic average presents some results which are impossible in real
life, like the arithmetic average of number of people getting down on a certain station can be
200.45. But in reality, never 200.45 people can get down in any station. similarly the number
of children per mother can be 2.7 but in reality this is impossible because number of children
can only be an whole number not 0.7.

Notes once a famous comic book ‘Panch’ has written that a royal Commission considered
the figure of 2.2 children as very foolish and the reason for this was thought as
the poor financial condition. Therefore, Royal Commission suggested that middle
class people must be given some financial aid so that they can raise the number of
children to a whole number and also increase them to a convenient number.

b. there is an ill effect of uncommon elements on the arithmetic average, especially when the
elements are very big or very small. for example, if in a class certain student obtains 100
marks in maths and the remaining 6 students obtain 20, 25, 19, 24, 15 and 28 marks then the
arithmetic average will be = 100 + 20 + 25 + 29 + 24 + 15 + 28 = 231 ÷ 7 = 33. But if we do
not include the student who has obtained 100 marks then the arithmetic average will be =
20 + 25 + 19 + 24 + 15 + 28 = 131 ÷ 6 = 22. therefore, it is evident that if there is a very big or
very small element in the series then the arithmetic average does not present a true picture
of the series.

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