It’s a matter of adding up and taking percentages
If you have a frequency table, you add a few columns to your table:
- Cumulative frequency
- Relative frequency
- Cumulative relative frequency
Cumulative frequency You add the frequencies up to and including for the value
Relative frequency You express the frequency as a fraction or percentage of total sum of frequencies
Cumulative relative frequency You express the cumulative frequency as fraction or percentage of the total sum of frequencies
Simple example Say you have frequencies: ##1-3-4-8-3-1## for 6 different values (total ##20##)
Then your relative frequencies will be: ##5%-15%-20%-40%-15%-5%##
Your cumulative frequencies will be: ##1-4-8-16-19-20##
And your cumulative relative frequencies will be: ##5%-20%-40%-80%-95%-100%##
