Page 88 - DECO504_STATISTICAL_METHODS_IN_ECONOMICS_ENGLISH

Statistical Methods in Economics

Notes Q– Q
Coeff. of Q.D. = 3 1
Q + Q 1
3
47.49 – 26.07
= = 0.2912
+
47.49 26.07
Answer: For the given data Q.D. = 10.71 and coeff. of Q.D. = 0.2912.
Example 11: Compute Quartile Deviation and its coefficient from the following data:

Mid-Value 3 4 5 6 7 8 9

Frequency 11 14 20 24 20 16 5

Solution:
Class f C.f.

2.5—3.5 11 11
3.5—4.5 14 25
4.5—5.5 20 45
5.5—6.5 24 69
6.5—7.5 20 89
7.5—8.5 16 105
8.5—9.5 5 110
Total N = 110

N 110
Q 1 = Size of 4 = 4 = 27.5 th item

27.5 th item which lies in 4.5—5.5 group

i
Q = 1 f ( l + q – c ) 1
1
1
= 4.5 + ( )27.5 – 25
20

2.5
= 4.5 +
20
= 4.5 + 0.125 = 4.625
3N 3 110 330
×
Q = Size of 4 = 4 = 4 = 82.5 th item
3
th
82.5 item which lies in 6.5 — 7.5 group.
i
Q 3 = l + ( 1 q – c ) 3
f

1
= 6.5 + ( )82.5–69
20

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