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Find the mean deviation about the mean of the following data: Size (x): 1 3 5 7 9 11 13 15 Frequency (f): 3 3 4 14 7 4 3 4

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Question

Find the mean deviation about the mean of the following data:

Size (x): 1 3 5 7 9 11 13 15
Frequency (f): 3 3 4 14 7 4 3 4
Sum
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Solution

Mean = `barx = (f_i  x_i)/(f_i)`

= `(3 + 9 + 20 + 98 + 63 + 44 + 39 + 60)/42`

= `336/42`

= 8

M.D. `(barx) = (f_i |x_i - barx|)/(f_i)`

= `(3(7) + 3(5) + 4(3) + 14(1) + 7(1) + 4(3) + 3(5) + 4(7))/42`

= `(21 + 15 + 12 + 14 + 7 + 12 + 15 + 28)/42`

= `62/21`

= 2.95

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Chapter 15: Statistics - Solved Examples [Page 272]

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NCERT Exemplar Mathematics Exemplar [English] Class 11
Chapter 15 Statistics
Solved Examples | Q 1 | Page 272

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