Question

Calculate quartile deviation for the following data:
$3,5,8,10,12,7,5$

Answer 1

Arranged data is

$3,5,5,7,8,10,12$

$Q_1=$ Value of ${\left(\frac{n+1}{4}\right)}^{th}$ term $=2^{nd}$ term$=5$

$Q_3=$ Value of ${\left(\frac{3n+3}{4}\right)}^{th}$ term $=6^{th}$ Term$=10$

$Q.D=\frac{Q_3-Q_1}{2}=2.5$