每组的下界可以通过从该组下限中减去间隙值 12=0.5 的二分一计算得出。另外，每组的上界可以通过该组上限加上间隙值 12=0.5 的二分一计算得出。
ClassFrequency(f)LowerLimitsLowerBoundariesUpperLimitsUpperBoundaries360−3692360360−0.5369369+0.5370−3793370370−0.5379379+0.5380−3895380380−0.5389389+0.5390−3997390390−0.5399399+0.5400−4095400400−0.5409409+0.5410−4194410410−0.5419419+0.5420−4294420420−0.5429429+0.5430−4391430430−0.5439439+0.5
