Jennifer Jones owns a small candy store she operates herself. A study was made observing the time between customers coming into the store and the time that Jones took to serve them. The following data were collected from 100 customers observed:

INTERARRIVAL TIME	NUMBER OF OBSERVATIONS	SERVICE TIME (MINUTES)	NUMBER OF OBSERVATIONS
1	5	1	10
2	10	2	15
3	10	3	15
4	15	4	20
5	15	5	15
6	20	6	10
7	10	7	8
8	8	8	4
9	5	9	2
10	2	10	1

Simulate the system (all of the arrivals and services) until 10 customers pass through the system and are serviced. How long does the average customer spend in the system? Use Appendix B to obtain random number.