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When tested, the lives (in hours) of 5 bulbs were noted as follows: 1357, 1090, 1666, 1494, 1623 The mean deviations (in hours) from their mean is ______. - Mathematics

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Question

When tested, the lives (in hours) of 5 bulbs were noted as follows: 1357, 1090, 1666, 1494, 1623 
The mean deviations (in hours) from their mean is ______.

Options

  • 178

  • 179

  • 220

  • 356

MCQ
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Solution

The mean deviations (in hours) from their mean is 178.

Explanation:

The lines of 5 bulbs are given by 1357, 1090, 1666, 1494, 1623

∴ Mean = `(1357 + 1090 + 1666 + 1494 + 1623)/5`

⇒ `barx = 7230/5` = 1446

`x_i` `d_i = |x_i - barx|`
1357 89
1090 256
1666 220
1494 48
1623 177
Total `sumd_i` = 890

∴ M.. = `(sumd_i)/n`

= `890/5`

= 178

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Chapter 15: Statistics - Exercise [Page 281]

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NCERT Exemplar Mathematics [English] Class 11
Chapter 15 Statistics
Exercise | Q 26 | Page 281

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