(3) Select the smallest observed value as the lower limit of the first class (e.g. the left hand value for the first class), and add multiples of the class width from step (2) to obtain the lower limits for each class. So in the black bear case, the lower class limits would be. 16.0, 26.2, 36.4, 46.6, , 107.8. (4) Find the upper class limits (the right hand value for each class) by adding the class width to the lower class limits and subtracting from this the smallest significant digit in the observations.