Mean deviation about mean from the following data:
xi: 3 9 17 23 27fi: 8 10 12 9 5,
is
6
7
8
9
Calculation of mean deviation about mean.
3
17
23
27
10
12
5
24
90
204
207
135
2
96
60
72
N=Σfi=44 Σfixi=660 Σfixi−15=312
mean =X¯=ΣfixiN=66044=15
Mean deviation =M⋅D⋅=1NΣfixi−15=31244=7.09≃7