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Find the mean deviation about the mean for the data. 4, 7, 8, 9, 10, 12, 13, 17

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Question

Find the mean deviation about the mean for the data.

4, 7, 8, 9, 10, 12, 13, 17

Sum
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Solution

Arithmetic mean `overline x = (4 + 7 + 8 + 9 + 10 + 12 + 13 + 17)/8`

= `80/8`

= 10

`sum |x_i - overline x| = |4 - 10| + |7 - 10| + |8 - 10| + |9 - 10| + |10 - 10| + |12 - 10| + |13 - 10| + |17 - 10|`

= 6 + 3 + 2 + 1 + 0 + 2 + 3 + 7 

= 24

∴ Mean deviation about the mean MD `(overline x) = (sum |x_i - overline x|)/n`

= `24/8`

= 3

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Chapter 13: Statistics - EXERCISE 13.1 [Page 270]

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NCERT Mathematics [English] Class 11
Chapter 13 Statistics
EXERCISE 13.1 | Q 1. | Page 270

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