1. Calculate Mean deviation about mode from the following grouped data

X	Frequency
10	3
11	12
12	18
13	12
14	3

Solution:

`x` `(1)`	`f` `(2)`	`|x-Z|=|x-12|` `(3)`	`f*|x-Z|` `(4)=(2)xx(3)`
10	3	2	6
11	12	1	12
12	18	0	0
13	12	1	12
14	3	2	6
---	---	---	---
--	`n=48`	--	`sum f*|x-Z|=36`

Mode :
the frequency of observation `12` is maximum (`18`)

`:. Z = 12`

Mean deviation of Mode
`delta bar x = (sum f*|x - Z|)/n`

`delta bar x = 36/48`

`delta bar x = 0.75`


Coefficient of Mean deviation `=(delta bar x)/(bar x)`

`=0.75/12`

`=0.0625`

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2. Calculate Mean deviation about mode from the following grouped data

X	Frequency
0	1
1	5
2	10
3	6
4	3

Solution:

`x` `(1)`	`f` `(2)`	`|x-Z|=|x-2|` `(3)`	`f*|x-Z|` `(4)=(2)xx(3)`
0	1	2	2
1	5	1	5
2	10	0	0
3	6	1	6
4	3	2	6
---	---	---	---
--	`n=25`	--	`sum f*|x-Z|=19`

Mode :
the frequency of observation `2` is maximum (`10`)

`:. Z = 2`

Mean deviation of Mode
`delta bar x = (sum f*|x - Z|)/n`

`delta bar x = 19/25`

`delta bar x = 0.76`


Coefficient of Mean deviation `=(delta bar x)/(bar x)`

`=0.76/2`

`=0.38`

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