FreeEconHelp.com, Learning Economics... Solved!: probability
Showing posts with label probability. Show all posts
Showing posts with label probability. Show all posts

3/9/12

Probabilities and drawing ping pong balls

00:50
Probabilities and drawing ping pong balls
This post will go over probability theory.   While not directly related to economics, probabilities and statistics are used in economics quite a bit.  Here is the question giving people problems:

There are two bags, each containing 1000 ping-pong balls. Bag A contains 1000 red balls and no black balls, and bag B contains 200 red and 800 black. You are blindfolded and reach into a bag. There is a .5 probability it is bag A and a .5 probability it is bag B. You draw a red ball. What is the probability that you drew the ball from bag A.