The width of each antonphak class does not need to be all equal. Depending on the purpose of use of information and the difference between the observed data set.
The width of each class interval is not necessarily equal. Depending on the intended use of the data and the difference between the value of the observation of the data set.
The width of each interval class need not all the same. Depending on the purpose of the use of information and the difference between the values from the observation of the data ชุดนั้น