My Math Forum  

Go Back   My Math Forum > High School Math Forum > Probability and Statistics

Probability and Statistics Basic Probability and Statistics Math Forum

LinkBack Thread Tools Display Modes
May 3rd, 2017, 09:03 AM   #1
Joined: Apr 2017
From: Philippines

Posts: 2
Thanks: 0

Several Bayesian Probability questions.

1.) If it rains, I do not go sailing. It rains 10% of days; I go sailing 3% of days.

If it does not rain, what is the (conditional) probability that I go sailing?

Written "p(I go sailing | it does not rain)''?

2.)I am at my office AND not working 2% of the time. I am at my office 10% of the time. What is the conditional probability that I am not working, if I am at my office?

3.) An Urn contains two white marbles and one black marble. A marble is drawn from the Urn without replacement and put aside without my seeing it. Then a second marble is drawn, and it is white.
What is the probability that the unknown removed marble is white, and what is the probability that it is black?

I would appreciate if you guys can provide a sound solution and a clear explanation. Thanks!
imsen2x is offline  
May 13th, 2017, 06:00 PM   #2
Senior Member
Joined: Oct 2013
From: New York, USA

Posts: 507
Thanks: 74

1. 90% of days it doesn't rain. The probability is 3%/90% = 1/30.

2. I think you're asking:

P (not working and at my office)/P (not working)

P (not working and at my office) = 2% * 10% = .002
P (not working and not at my office) = 90% = .900

P (not working and at my office)/P (not working) = .002/(.002 + .900) = .002/.902 = 2/902 = 1/451 = .002217294900222

3. I was starting to post multiple steps, but they're not necessary. If the second marble is white, the first marble and the marble not picked are one black and one white in some order, so the probabilities for the first marble are 1/2 each.
EvanJ is offline  

  My Math Forum > High School Math Forum > Probability and Statistics

bayesian, probability, questions

Thread Tools
Display Modes

Similar Threads
Thread Thread Starter Forum Replies Last Post
Probability questions Saralove996 Advanced Statistics 2 November 4th, 2014 05:01 AM
Probability questions neilduggan Advanced Statistics 1 November 9th, 2013 12:11 PM
questions in probability r-soy Probability and Statistics 4 October 14th, 2013 04:46 AM
Bayesian Networks: Probability exercise help needed. Angroid Advanced Statistics 1 October 16th, 2012 04:09 AM
Bayesian or not Bayesian; this is my problem! Marione Advanced Statistics 0 April 24th, 2008 02:51 PM

Copyright © 2017 My Math Forum. All rights reserved.