Question

If the lower and upper quartiles of a data are $4$ and $12$, then the quartile deviation is ____

• A. $2$
• B. $4$
• C. $6$
• D. $8$

Answer 1

Answer: (B)

$4$

Quartile deviation is the half of the inter quartile deviation.

Inter quartile deviation is the difference between upper quartile and lower quartile.

Given that, lower quartile is $4$ and upper quartile is $12$

Therefore, Quartile deivation is $\frac{\text{upper quartile - lower quartile}}{2}$

$⟹\text{quartile deviation}=\frac{12-4}{2}=\frac{8}{2}=4$