# Answer all 3 questions

Q3.

Let "n" be the required number of observations.

Σ(x

_{ i - }4) = 72, therefore, Σx

_{i}- 4n = 72 ....... (1)

And,

Σ(x

_{i}- 7) = -3, therefore, Σx

_{i}- 7n = -3 ........ (2)

Subtracting the above two equations we get,

3n = 75

n = 25

Q2.

Standard deviation and mean deviation are the two methods of dispersion.

Regards,

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