Results 1 to 4 of 4
Like Tree1Likes
  • 1 Post By river_rat

Thread: Probability Question:

  1. #1 Probability Question: 
    Forum Freshman ClaimingLight's Avatar
    Join Date
    Jun 2012
    Say I rolling X number of 6 sided-dice. I'm attempting to get >=Y number of results of 5 or greater.

    For instance, I'm trying to roll three dice and get two or more events. What's a reliable algorithm to determine the likelihood of that occurring? I'm trying to find a way to extrapolate that question for a game I'm making- so I can later apply it to four or five dice.

    I approve this message.
    Reply With Quote  


  3. #2  
    Forum Professor river_rat's Avatar
    Join Date
    Jun 2006
    South Africa
    Do you know about the Binomial Distribution?

    ClaimingLight likes this.
    As is often the case with technical subjects we are presented with an unfortunate choice: an explanation that is accurate but incomprehensible, or comprehensible but wrong.
    Reply With Quote  

  4. #3  
    Forum Freshman ClaimingLight's Avatar
    Join Date
    Jun 2012
    When I was doing some initial research, I found something on wikipedia about it. Couldn't make much sense of it though. I did find a binomial distribution calculator that may be able to sort this problem for me. It asks me for number of events, number of successes and probability.

    For it to be useful to me, I have to assume that the probability of success part is per one die rolled... which must mean that an event is a single die. Number of successes... is that the number of required successes? Because... yeah, that'd be nice.
    Hmm. Tried it out with 3 dice, 33% for a success and req for 2 successes. It gave me 21.9%. My long hand came up with 25.9% I must not be doing this right.
    Binomial Distribution Probability Calculator Online

    I think I figured out why that is. It seems the Binomial Distribution only tests for an exact number of successes. Over three dice, I'm looking for the percentage of 2+ successes. I wonder if there's anything in that vein?

    Edit 2:
    Ok- I think I found what I'm looking for. This calculator tracks the cumulitive d
    istributionin multiple ways. If anyone needs it in the future, here it is.
    Last edited by ClaimingLight; October 25th, 2012 at 05:42 PM.
    I approve this message.
    Reply With Quote  

  5. #4  
    Forum Professor wallaby's Avatar
    Join Date
    Jul 2005
    Quote Originally Posted by ClaimingLight View Post
    For it to be useful to me, I have to assume that the probability of success part is per one die rolled...

    The probability of success should be the probability that a single dice roll returns a value of 5 or higher, for a six sided die this should be . Given X die are rolled, then the probability of Y successes is given by the following equation.


    is the number of combinations of 2 objects, drawn from a total of three objects. So for 3 dice the probability of 2 successes should be , the discrepancy between this answer and that of the calculator most likely being due to round off error.
    Reply With Quote  

Similar Threads

  1. Replies: 0
    Last Post: May 30th, 2012, 03:05 PM
  2. probability question 2
    By 15uliane in forum Physics
    Replies: 9
    Last Post: August 11th, 2011, 11:53 AM
  3. Probability
    By Heinsbergrelatz in forum Mathematics
    Replies: 0
    Last Post: February 28th, 2011, 04:38 AM
  4. Replies: 1
    Last Post: June 14th, 2007, 08:51 AM
  5. Probability Question
    By Drewau2005 in forum Mathematics
    Replies: 1
    Last Post: April 5th, 2007, 04:21 AM
Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts