Mathematics · supplementary
Quartiles for grouped data for JEE
Measures of dispersion; calculation of mean, median, mode of grouped and ungrouped data
Formula
\(Q_k=l+\left(\frac{\frac{kN}{4}-c_f}{f}\right)h,\ k=1,3\)
Variables: \(l\): lower boundary of quartile class, \(N\): total frequency, \(c_f\): cumulative frequency before quartile class, \(f\): frequency of quartile class, \(h\): class width.
Conditions: Quartile class determined using \(N/4\) or \(3N/4\).
Finding quartiles in grouped data.