Question

Coefficient of quartile deviation of numbers $6,8,9,10,11,12,14$ is?

• A. $1/5$
• B. $1/10$
• C. $2/5$
• D. $1/4$

Answer 1

The correct option is A $1/5$

Arranging given numbers in ascending order,

$6,8,9,10,11,12,14$

Number of observation $\left(N\right)=7$

$Q_i={\left\{i\left(\frac{N+1}{4}\right)\right\}}^{th}term$

$Q_1={\left\{1.\left(\frac{7+1}{4}\right)\right\}}^{th}term=2^{nd}term$

$2^{nd}term=8$

$\therefore$ $Q_1=8$

$Q_3={\left\{3.\left(\frac{7+1}{4}\right)\right\}}^{th}term=6^{th}term$

$6^{th}term=12$

$\therefore$ $Q_3=12$

$\Rightarrow$ Coefficient of quartile $=\frac{Q_3-Q_1}{Q_3+Q_1}$

$=\frac{12-8}{12+8}$

$=\frac{4}{20}$

$=\frac{1}{5}$