# Q: Most Likely!

Discussion in 'Probability' started by Geoff Jones, Jul 7, 2004.

1. ### Geoff JonesGuest

Hi

I was wondering if anybody could give me some thoughts on the following
problem:

Suppose we have two radioactive particles which emit particles at a given
rate. Suppose also that we have two Geiger counters a certain distance from
both particles. Let us denote the "strength" of the particles by Si (where i
is an index for the particle). Let us also denote the distance of the Geiger
counter j to the particle i as Dij. Suppose also that the probability of a
counter receiving a "hit" from particle i is inversely proportional to the
distance from it.

If one of the Geiger counters records a "hit" from one of the radioactive
sources, how do we work out which one is the most likely one?

Geoff

Geoff Jones, Jul 7, 2004

2. ### jeffcGuest

It totally depends on how the distance affects the result and how the
strength affects the result. It's kind of arbitrary without that knowledge.
But basically the probability of a hit from particle i is going to be
proportional to the strength and inversely proportional to the distance.
Like P(i) is Si/Dij, with some extra stuff thrown in to make the 2
probabilities add up to 1.

jeffc, Jul 13, 2004