Thread: expectation

Hi anyone knows how to solve this:

a) The mean time between taxis arrivals is 20 minutes and I arrive to the taxis stop at a random point of time. How long do I have to wait in average?

b) And what would be the average if the taxis arrived according to a Poisson process??


Thank you

Originally Posted by mosquetero

Hi anyone knows how to solve this:

a) The mean time between taxis arrivals is 20 minutes and I arrive to the taxis stop at a random point of time. How long do I have to wait in average?

The arrivals are independent of one another so the expected wait will still be 20 minutes

b) And what would be the average if the taxis arrived according to a Poisson process??

The intervals between arrivals of a process where the number of arrivals per hour has a Poisson distribution has an exponential distribution, so the arrival intervals are stilll exponential and you will still have an expected waiting time of 20 minutes.

CB