NCERT Class XI Mathematics - Statistics - Solutions

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Question : 5
Total: 34
xi5 10 15 20 25
fi 7 4 6 3 5

Solution:  
xi 5 10 15 20 25
fi 7 46 3 5 25
fixi 35 4090 60 125 350
|xi14|9 4 1 6 11
fi|xi14| 63 16 6 18 55158

Mean (
x
)
=
1
N
n
Σ
i=1
fi
xi
=
1
25
×350
= 14
∴ Mean deviation about mean =
1
N
n
Σ
i=1
fi
|xi
x
|
=
1
25
× 158 = 6.32
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