how to calculate random number, time between calls and cumulative clock using excel for this problem.

Probability of Time between calls			Simulation
P(x)	Cumulative (lower bound)	Time between calls		simulation Number	RN	Time between calls	Cumulative clock
0.15	0.15	1		1
0.1	0.25	2		2
0.2	0.45	3		3
0.25	0.7	4		4
0.2	0.9	5		5
0.1	1	6		6
1				7
				8
EV =	3.55			9
Average Time =				10
				11
				12
				13
				14
				15
				16
				17
				18
				19
				20