what is a cumulative frequency diagram used for
Cumulative frequency is used to determine the number of observations that lie above (or below) a particular value in a data set.The cumulative frequency is calculated using a frequency distribution table, which can be constructed from stem and leaf plots or directly from the data.The cumulative frequency is calculated by adding each frequency from a frequency distribution table to the sum of its predecessors.se the Frequency column to calculate cumulative frequency. 1  First, add the number from the Frequency column to its predecessor. 2  For example, in Stem 0, we have only one observation and no predecessors. 3  The cumulative frequency is one. 4  1 + 0 = 1. 5  However in Stem 1, there are two observations.