Illustration
In a social survey whether the main reason was to establish the intelligence quotient or IQ of resident in a provided area, the given results were acquired as tabulated below as:
|
IQ
|
No. of residents
|
Upper class bound
|
CF
|
|
1 - 20
|
6
|
20
|
6
|
|
21 - 40
|
18
|
40
|
24
|
|
41 - 60
|
32 fo
|
60
|
56
|
|
61 - 80
|
48 f1
|
80
|
104
|
|
81 - 100
|
27 f2
|
100
|
131
|
|
101 - 120
|
13
|
120
|
144
|
|
121 - 140
|
2
|
140
|
146
|
Required
Estimate the modal value of the IQ's tabulated as given above using
i. The graphical method
ii. Formular