Poisson Distribution question
Can someone help me with part c?
The number of people arriving for treatment at an emergency room can be modeled by a Poisson process with a rate parameter of five per hour.
a) What is the probability that exactly four arrivals occur during a particular hour?
P(X=4)= = .17547
b) What is the probability that at least four people arrive during a particular hour?
1 - P(X=3) - P(X=2) - P(X=1) - P(X=0) = 1 - .14037 - .08422 - .03369 - .00674 = .73498
c) How many people do you expect to arrive during a 45-minute period?
, if =5/hr and t = 3/4 hr we get 15/4. Do we take the floor, round up if > .5, or take the ceiling? I can't find the answer in my notes, or in the text.