your table would look like this:
x distribution of x cumulative distribution of x. 1 20% 20% 2 20% 40% 3 20% 60% 4 20% 80% 5 20% 100%
the cumulative distribution includes all the previous distributions as well.
here's a refeence.
http://stattrek.com/statistics/charts/cumulative-plot.aspx
here's a definition of cumulative by merriam webster.
http://www.merriam-webster.com/dictionary/cumulative
cumulative comes from accumulate.
when your next interval adds the data from the previous interval, then you have cumulative data.
the following excel output shows the tablel and graph of a distribution and its cumulative distribution.
