Range is defined as the difference between the two extreme values of a series.

Thus, Absolute Range = Largest value – Smallest value

or R= L-S

And Co-efficient of range or Coeff.R = L-S/L+S

Where, L = largest value of a series

And, S = Smallest value of a series

It is to be noted that a Range has nothing to do with the frequencies of a series. It is found out purely on the basis of the two extreme values of a series.

In case of a continuous series**, **the Range is worked out by taking the difference between the upper limit of the largest class interval, and the lower limit of the smallest class interval. In such a case, the Range is given by

R = L_{2(L)} – L_{1(S)} ;

And its co-efficient by

Coeff. R = L_{2(L)} – L_{1(s)/} L_{2(L) }+ L_{1(s) }

However, in such cases, Range can also be computed by taking the difference between the mid-value of the largest class, and the mid-value of the smallest class, where,

Range is represented by

R = X(L) – X (S) = L-S

And its co-efficient by