1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Dice and probability

  1. Apr 21, 2013 #1
    Pour an ordinary dice 129 times and let X the sum of all indications that it brings.

    Let p=P(X<=12)

    What is the minimum upper bound for the probability p resulting from inequality of Chebyshev;

    Note: The probability density of X is symmetric about the mean value of X


    how i can find the fX(x) of the sum of all indications that brings the dice if we roll it 129?
     
  2. jcsd
  3. Apr 21, 2013 #2

    Ray Vickson

    User Avatar
    Science Advisor
    Homework Helper

    The question is unclear. Do you toss a single die 129 times (each time getting a number from 1 to 6), or do you toss a pair of dice 129 times (each time getting a number from 2 to 12)?

    Anyway, you need to show your work first before we can help.
     
  4. Apr 21, 2013 #3
    we toss a dice 129 times, but i cant think how to find the E(X) and Var(X) of this thats why i aksed for help...
    i will estimate any sum? from 1 to 129?
     
  5. Apr 21, 2013 #4

    Ray Vickson

    User Avatar
    Science Advisor
    Homework Helper

    You still have not described your problem in meaningful terms: the words "a dice" are contradictory. The "a" means one but the word "dice" means 2 or more. If you toss just one cube with faces numbered 1--6 you are tossing one die (NOT dice); if you toss two such cubes (giving a total from 2--12 in each toss) you are throwing dice = more than one die. So, which do you mean?
     
  6. Apr 22, 2013 #5
    we toss one dice 129 times not two...
     
  7. Apr 22, 2013 #6

    Ray Vickson

    User Avatar
    Science Advisor
    Homework Helper

    No, you don't. You toss one die 129 times. You are tossing a DIE, not DICE.
     
  8. Apr 22, 2013 #7
    yea anyway , how i am gonna estimate the expected value of the random variable X which is the sum of all outcomes i am confused
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Dice and probability
  1. Dice Probability (Replies: 11)

  2. Dice Probability (Replies: 13)

  3. Probability with dice (Replies: 2)

Loading...