Please give the steps for the calculation of the obtained answer.

Class Class 1 Class 2 Class 3 Class 4 Class 5 Class 6 Frequency 30 10 50 F H J Relative frequency 0.15 0.05 0.25 0.45 G I Cumulative relative frequency 0.15 0.20 0.45 E 0.98 1.00