Results 1 to 2 of 2

Math Help - Probabilities

  1. #1
    Newbie
    Joined
    Sep 2008
    Posts
    3

    Angry Probabilities

    A sensitive machine is tuned correctly for 95% of the time. If the machine is correctly tuned, the probability of a spoilt product is 1%; if not, it is 40%. The first product of a test run is inspected and found to be satisfactory.

    What is the probability that the machine had been correctly tuned?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Newbie
    Joined
    Sep 2008
    Posts
    2
    Quote Originally Posted by gibonwa33 View Post
    A sensitive machine is tuned correctly for 95% of the time. If the machine is correctly tuned, the probability of a spoilt product is 1%; if not, it is 40%. The first product of a test run is inspected and found to be satisfactory.

    What is the probability that the machine had been correctly tuned?
    We need to use conditional probabilities here.
    P(Machine correctly tuned | product not faulty) = 0.95 * 0.99/(0.95 * 0.99 + 0.05 * 0.6)

    =~ 0.97

    where
    0.95 * 0.99 = Prob of Machine correctly tuned and product not being faulty
    denominator = Overall Probability of the machine being non faulty
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 3
    Last Post: September 22nd 2011, 10:46 AM
  2. Approximate joint probabilities using marginal probabilities
    Posted in the Advanced Statistics Forum
    Replies: 0
    Last Post: June 23rd 2011, 05:04 AM
  3. Probabilities
    Posted in the Statistics Forum
    Replies: 2
    Last Post: November 30th 2009, 09:24 PM
  4. more probabilities
    Posted in the Statistics Forum
    Replies: 1
    Last Post: November 30th 2009, 04:14 PM
  5. Probabilities...
    Posted in the Advanced Statistics Forum
    Replies: 1
    Last Post: December 7th 2008, 04:29 AM

Search Tags


/mathhelpforum @mathhelpforum