Step-deviation method for mean for JEE

Formula

\(\bar{x}=a+h\frac{\sum f_i u_i}{\sum f_i}\), \(u_i=\frac{x_i-a}{h}\)

Variables: \(a\): assumed mean, \(h\): common factor/class width, \(x_i\): value or class mark, \(f_i\): frequency.

Conditions: Useful when deviations are multiples of a common number \(h\).

Grouped data with equal class widths.