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Find the mean deviation about the mean for the data. xi 10 30 50 70 90 fi 4 24 28 16 8 - Mathematics

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Question

Find the mean deviation about the mean for the data.

xi 10 30 50 70 90
fi 4 24 28 16 8
Sum

Solution

xi fi fixi `|"x"_"i" - bar"x"|` `"f"_"i"|"x"_"i" - bar"x"|`
10 4 40 40 160
30 24 720 20 480
50 28 1400 0 0
70 16 1120 20 320
90 8 720 40 320
Sum 80 4000 - 1280

`overline "x" = (sum"f"_"i""x"_"i")/(sum"f"_"i")` 

= `4000/80`

= 50

Mean Deviation = `(sum"f"_"i" |"x"_"i" - overline"x"|)/"N"`

= `1280/80`

= 16

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Chapter 15: Statistics - Exercise 15.1 [Page 360]

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NCERT Mathematics [English] Class 11
Chapter 15 Statistics
Exercise 15.1 | Q 6 | Page 360

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