Can someone tell me how to get the correct answer to this statistics question using excel formula.
The question is: Recalling the relationship between the Poisson and exponential distributions, find the probability that the time between two successive customer arrivals is more than four minutes. The poisson distribution has an expected arrival rate of 20 customers per hour.
Using that i set up this formula in excel:
More than four minutes = 1- EXP.Dist(4,20,true) --- answer is 1
Two minutes= EXP.Dist(2,20,true)----answer is 0
The problem is I am not getting the correct values. I know the correct values. I am just not sure how to get that answer in excel.
The correct values should be:
More than four minutes = 0.26
Two minutes = 0.49
Can someone explain what i am doing wrong as far as setting up the equation in excel.