How do you find the cumulative relative frequency?

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%##