Question

Find the third quatile (Q3) if quartile deviation (QD) = 2.5
and first quartile (Q1.) = 18​

Answer 1

qd = q3- q1/ 2

or, 2.5= q3- 18/ 2

or, 2.5× 2 = q3- 18

or, 5= q3- 18

or,q3= - 18 + 5

:. q3= 13