Given that the Absolute frecuency is the number of times that the value of a sample of the population appears, the accumulated absolute frequency is the result of all the sums of the absolute frequencies (redundancy is worth). This concept, which is key to understanding the study of statistics, is represented by the acronym Fi.
How is the cumulative absolute frequency calculated?
Given a sample of N elements, the sum of all the absolute frequencies should give the total of the studied sample: N. Therefore, the accumulated absolute frequency would be the sum of each and every one of the absolute frequencies for all equal events or earlier than a value. Therefore, if we want to calculate this frequency we will have to do it from quantitative variables or quantitative variables that can be ordered.
By knowing how many items in a data list are less than or equal to a given value, we can question whether the cumulative frequency distribution is valid for making long-term predictions. If that distribution is not valid, the forecast could be subject to random error.
How is the cumulative absolute frequency different from the relative?
Just as the accumulated absolute frequency is the sum of the absolute frequencies of all values equal to or less than the value studied, the relative frequency Cumulative is the result of dividing the cumulative frequency by the number of data in the study. That is, the only difference that exists between both variables is that the accumulated relative frequency is calculated by dividing between the total number of observations (which will facilitate the task to unsuspected limits, since we will not have to add one by one absolute frequencies).
Finally, both variables are represented by the abbreviations Fi and Ni, respectively.