4 customers waited 2 minutes or less. 10 customers waited 4 minutes or less. 16 customers waited 6 minutes or less. 22 customers waited 8 minutes or less. All 25 customers waited 10 minutes or less.

Cumulative frequency is a running total of the frequencies. This can be represented on a graph by plotting the upper boundary of the groups. To create a cumulative frequency table all we need to do is ...