A store selling newspapers only orders n4 of a certain newsp

A store selling newspapers only orders n=4 of a certain newspaper because the manager does not get many calls for that publication. If the number of request per day follows a Poisson distribution with mean 3,

a) What is the expected value of the number sold?

b) How many should the manager order so that the chanceof running out is less that .05?

Solution

So, expected selling = sum(xP(x)) = 1.94**

** your answer might be wrong.

0.99970766

To avoid running out status from 0.05 level chance,

then cululative probability at n=6 is 0.9664,

So n=6 to be ordered.