Question 1086754
Question:
Jack and Jill work in the school office. They are recording and analysing the number and length of phone calls received. The number of telephone calls that are answered by the office has a mean of 12 calls per hour.
a) Find the probability that there are no calls in any given 15 minute interval.
I need to use distribtuions on a scientific caclulator but I don't know which to use, I tried poisson and binomial but it didn't work.
 
Solution:
Wonder if you did the same as following when you worked on the Poission distribution.
For a 15 minute period, the average number of calls is λ=12/4=3
P(k=0 calls within period)
=Pmf_Poisson(0,3)
=λ^k (e^(-λ)/k!
=3^0 (e^(-3)/0!
=1*e^(-3)/1
=e^(-3)
=0.0498