The lower limit for every class is the smallest value in that class. On the other hand, the upper limit for every class is the greatest value in that class.
ClassFrequency(f)LowerLimitsUpperLimits19.55−21.82319.5521.8221.83−24.1521.8324.124.11−26.38924.1126.3826.39−28.66626.3928.6628.67−30.94228.6730.94