Page 238 - DSOC404_METHODOLOGY_OF_SOCIAL_RESEARCH_ENGLISH

Methodology of Social Research

notes score frequency Variation d’ of scores from F x d’ = fd f d’ x d’
(x) (f) assumed Mean A = 10

21 1 11 11 121

20 0 10 0 0
19 0 9 0 0
18 2 8 16 128
17 1 7 7 49
16 2 6 12 72

15 3 5 15 75
14 2 4 8 32
13 3 3 9 27
12 4 2 8 16

11 6 1 6 6
10 8 0 0 0
9 7 –1 –7 7
8 5 –2 –10 20

7 2 –3 –6 18
6 1 –4 –4 16
5 3 –5 –15 75
(NSf) = 50 Sfd’ = 50 Sfd’ = 662

S ' d 2  S ' d  2
(σ) = N −   N  

Sfd’ 2 = 662,
Sfd’ = 50 N = 50

662  50  2
(σ) = −  
50  50 
= 13.24 1
−
= 12.24
= 3.5 (Approx.)

(c) continuous series

Example 6 the given table shows the distribution of population for different age groups
in a city. find out the standard deviation (s.D.)

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