Homework Help: Last stat question nearly done

1. Apr 10, 2014

ivan_x3000

1. The problem statement, all variables and given/known data
Of all archers at one particular competition
50% are local (1/2)
40% come from another state (2/5)
10% are international (1/10)

At the end of the competition some of the archers choose to go on a specially organised bus tour

Of the locals 35% go on the tour (35/100)
of those from another state 45% go on the tour (45/100)
of those from overseas 75% go on tour (75/100)

At the end of the tour, an unlabelled bag is found on the bus.
What is the probability the bag belong to a local

2. Relevant equations
Have to choose between bernoulli, binomial, poisson, geometric, hyper geometric and negative binomial methods

3. The attempt at a solution

P of a local is going to the tour is (1/2)(35/100)= 7/40
P of not being a local is (1-7/40)= 33/40

Assuming: probability is constant for all, independent,

is the the probability (7/40)(33/40)= 231/1600 by bernoulli method

2. Apr 10, 2014

ivan_x3000

Actually nah new idea... use a tree diagram and it's a 0.5*0.35

3. Apr 10, 2014

Ray Vickson

Who says you have to choose between bernoulli, binomial, poisson, geometric, hyper geometric and negative binomial? None of these have anything at all to do with the given problem. Anyway, those named things are not "methods"; they are distributions.

4. Apr 14, 2014

ivan_x3000

So... what did you did think of my answer haha 0.5*0.35