An ISP provider offers special discounts to every 3rd connecting customer. Its customers connect according to a Poissan process, with lambda = 5 customers per minute.
a) What is the probability that no offer is made during the first 2 minutes?
Since lambda is 5 per minute, i doubled it to 10 (since its for 2 minutes) then just evaluated the P(x=0) to get a very small decimal number...i think this is right
b) What is the expectation and variation of the time of the first offer?
I'm stuck here...I think the expected value of the time of the first offer is .6 minutes, since there are an expected 5 connections per minute, and one offer every 3 connections (so 3/5 = 0.6), is this right? If so, how would I find the variance?