Page 72 - DECO504_STATISTICAL_METHODS_IN_ECONOMICS_ENGLISH

Statistical Methods in Economics

Notes Grouping Table

Weight No. of persons
(in lb.) Col. 1 Col. 2 Col. 3 Col. 4 Col. 5 Col. 6

100 — 110 4
10
110 — 120 6 26
30
120 — 130 20 58 85
52
130 — 140 32 65
140 — 150 33
50
150 — 160 17 82
25 58
160 — 170 8 27
10
170 — 180 2

Analysis Table

Col. No. Class in which mode is expected to lie
120 — 130 130 — 140 140 — 150

I 1
II 1 1
III 1 1
IV 1 1
V 1 1 1
VI 1 1 1

Total 3 5 5
This is a bimodal series. Hence mode has to be determined indirectly by applying the formula:
Mode = 3 Median – 2 Mean.

N 122
Median = Size of th item = = 61st item.
2 2
Hence median lies in the class 130 — 140.

cf
N/2 − . .
Median = L + f × i
L = 130, N/2 = 61; c.f. = 30, f = 32, i = 10.

61 − 30 310
Median = 130 + × 10 = 130 + = 130 + 9.69 = 139.69 lb.
32 32

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