Quartile deviation for a frequency distribution is
Find Quartile deviation of the following table
As median divides an arranged series into two equal parts, in similar way quartile divides an arranged series in 4 equal part. For ungrouped frequency distribution formula of finding ith quartile = Q ={i.((N+1)/4)}^(th) term, i = 1, 2, 3.term, i = 1, 2, 3. Quartile deviation : half of difference between upper quartile & lower quartile. Quartie deviation (Q.D)=1/2(Q_3-Q_1) Coefficient of quartile deviation = ((Q_3-Q_1)/(Q_3+Q_1)). If 1, 2, 3, 4, 5, 6, 7, are numbers then Q_1 & Q_3, are respectively
