Range

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