There are 60 infections in village A per month and 48 infections in village B per month.
Let A be no of infections in village A per month and B be no of infections in village B per month. Assume occurrence is independent and random.
Method 1 (Working method):
A~Po (60) and B~Po (48)
Using a suitable approximation, find the probability that in 1 month, the no of infections in B exceeds no of infections in A.
Since λ>10, A~ N(60,60) and B~N(48,48) approximately
This I can understand but when I tried another method, it didnt work.
Method 2: Through linear combination of poisson (???Cannot get it to work???)
A-B ~ Po(12)
Since λ>10, A-B~N(12,12)