An equal width grouped FDT with width w is constructed for a dataset whose measurement unit is 10 P,p = 0, 1,2,. ... If LL, and UL; are lower and upper limits of the ith -class of the FDT, then (based on the way to construct an equal width grouped FDT taught in class) UL; - LL; equals w+ 10-P 1- 5 x 100-1 2 - 20 w + 10* w - 10-P.