Originally Posted by Mike Oxbigger
Please check this for me cause i'm missing a zero in my answer
If an average of 0.5 customers arrive per minute at a ticket counter, what is the probability that exactly 4 customers will arrive in a 5 minute span
a. 0.0534
b. 0.50
c. 0.68
d. 0.134
I got 0.534 which is just like a. w/o the 0 but rounded down would be b., I did it a couple times on my calculator and thats what i get
Answer is (d) kind sir
You have 0.5 arriving per minute... so 2.5 arrive every 5 minutes.
Doing P(X=4) we get (2.5^4 * e^-2.5)/4! = 0.134
The Poisson formula is basically:
P(X=n) = (mean^n * e^-mean)/n!