The following values are calculated in respect of heights and weights of the students of a section of Class $\mathrm{XI}:$

  Height Weight
Mean $162.6\,cm$ $52.36\,kg$
Variance $127.69\,c{m^2}$ $23.1361\,k{g^2}$

Can we say that the weights show greater variation than the heights?

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To compare the variability, we have to calculate their coefficients of variation.

Given $\quad$ Variance of height $=127.69 cm ^{2}$

Therefore Standard deviation of height $=\sqrt{127.69} cm =11.3 cm$

Also $\quad$ Variance of weight $=23.1361 kg ^{2}$

Therefore Standard deviation of weight $=\sqrt{23.1361} kg =4.81 kg$

Now, the coefficient of variations $(C.V.)$ are given by

$(C.V.)$ in heights $=\frac{\text { Standard } \text { Deviation }}{\text { Mean }} \times 100$

$=\frac{11.3}{162.6} \times 100=6.95$

and $\quad$ $(C.V.)$ in weights $=\frac{4.81}{52.36} \times 100=9.18$

Clearly $C.V.$ in weights is greater than the $C.V.$ in heights

Therefore, we can say that weights show more variability than heights

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