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In any discrete series (when all values are same), the relationship between MD about mean and SD is

  • Option 1)

    MD = SD

  • Option 2)

                MD ³ SD

  • Option 3)

    MD < SD

  • Option 4)

    MD £ SD

 

Answers (1)

best_answer

As we learned

 

DISPERSION -

Dispersion means scatteredness, Dispersion measures the degree of scatteredness of the variable about its central value.

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 Let xi/fi; i  = 1, 2,…………., n be a frequency distribution.

Then SD = \sqrt{\frac{1}{N}\sum_{i=1}^{n}\oint_{i}(x_{i}-\bar{x})^{2}}

and  MD = \frac{1}{N}\sum_{i=1}^{n}\oint_{i}|x_{i}-\bar{x}|^{2}

let |x_{i}-\bar{x}|^{2}=z_{i};i=i,2.....n.

Then, (SD)^{2}-(MD)^{2}

=MD = \frac{1}{N}\sum_{i=1}^{n}\oint_{i}z_{i}^{2}-\left [ \frac{1}{N}\sum_{i=1}^{n}\oint_{i}z_{i}\right ]^{2}=\sigma ^{2}\geq 0

Þ         SD ³ MD

 


Option 1)

MD = SD

Option 2)

            MD ³ SD

Option 3)

MD < SD

Option 4)

MD £ SD

Posted by

Himanshu

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