Results 1 to 9 of 9

Math Help - roll of the die

  1. #1
    Newbie
    Joined
    Jul 2006
    Posts
    17

    roll of the die

    Even number = that number is added to your score

    Odd number = that number subtracted from your score


    What is the expected value of a single roll of the die, and how is it calculated?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor Quick's Avatar
    Joined
    May 2006
    From
    New England
    Posts
    1,024
    Quote Originally Posted by zoso
    Even number = that number is added to your score

    Odd number = that number subtracted from your score


    What is the expected value of a single roll of the die, and how is it calculated?
    Tell me, what is the average score of all the possible outcomes?

    I'll show you...

    note: s_1 is the amount of points you'll get when you roll a 1

    average is:

    \frac{s_1+s_2+s_3+s_4+s_5+s_6}{6}=\frac{\neg1+2-3+4-5+6}{6}=\frac{3}{6}=\boxed{\frac{1}{2}}

    and that is the expected outcome for a single roll of the die. Yes I know it's impossible to get that number with a die, but that's the best math has to offer.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Super Member malaygoel's Avatar
    Joined
    May 2006
    From
    India
    Posts
    648
    Quote Originally Posted by zoso
    Even number = that number is added to your score

    Odd number = that number subtracted from your score


    What is the expected value of a single roll of the die, and how is it calculated?
    Expected value of a single roll of dice is 3.5

    Malay
    Follow Math Help Forum on Facebook and Google+

  4. #4
    MHF Contributor Quick's Avatar
    Joined
    May 2006
    From
    New England
    Posts
    1,024
    Quote Originally Posted by malaygoel
    Expected value of a single roll of dice is 3.5

    Malay
    oooooh, conflict. How would you find 3.5 as an answer if that is higher than the expected outcome if all numbers counted as positive?
    Last edited by Quick; July 18th 2006 at 08:44 PM.
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Super Member malaygoel's Avatar
    Joined
    May 2006
    From
    India
    Posts
    648
    Quote Originally Posted by Quick
    oooooh, conflict. How would you find 3.5 as an answer if that is higher than the expected outcome if all numbers counted as positive?
    There are six numbers and the probability of any one of them is 1/6.
    Hence expected value= \frac{1}{6}.1 + \frac{1}{6}.2 + \frac{1}{6}.3 + \frac{1}{6}.4 + \frac{1}{6}.5 + \frac{1}{6}.6

    Malay
    Follow Math Help Forum on Facebook and Google+

  6. #6
    Newbie
    Joined
    Jul 2006
    Posts
    17
    Quote Originally Posted by Quick
    Tell me, what is the average score of all the possible outcomes?

    I'll show you...

    note: s_1 is the amount of points you'll get when you roll a 1

    average is:

    \frac{s_1+s_2+s_3+s_4+s_5+s_6}{6}=\frac{\neg1+2-3+4-5+6}{6}=\frac{3}{6}=\boxed{\frac{1}{2}}

    and that is the expected outcome for a single roll of the die. Yes I know it's impossible to get that number with a die, but that's the best math has to offer.
    blatantly simple, I really need to think more
    Follow Math Help Forum on Facebook and Google+

  7. #7
    MHF Contributor Quick's Avatar
    Joined
    May 2006
    From
    New England
    Posts
    1,024
    Quote Originally Posted by malaygoel
    There are six numbers and the probability of any one of them is 1/6.
    Hence expected value= \frac{1}{6}.1 + \frac{1}{6}.2 + \frac{1}{6}.3 + \frac{1}{6}.4 + \frac{1}{6}.5 + \frac{1}{6}.6

    Malay
    You didn't read the entire question, if the number is odd, than it's subtracted from the score.
    Follow Math Help Forum on Facebook and Google+

  8. #8
    Super Member malaygoel's Avatar
    Joined
    May 2006
    From
    India
    Posts
    648
    Quote Originally Posted by Quick
    You didn't read the entire question, if the number is odd, than it's subtracted from the score.
    Sorry
    Yes, if it is to be subtracted. then the answer is 0.5.

    Malay
    Follow Math Help Forum on Facebook and Google+

  9. #9
    Super Member malaygoel's Avatar
    Joined
    May 2006
    From
    India
    Posts
    648
    Quote Originally Posted by zoso
    blatantly simple, I really need to think more
    You are correct here.
    Extend it.
    Try for double throw of dice.

    Malay
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 6
    Last Post: May 28th 2011, 11:48 PM
  2. roll of ribbon
    Posted in the Algebra Forum
    Replies: 2
    Last Post: August 12th 2010, 05:25 PM
  3. probability die roll
    Posted in the Advanced Statistics Forum
    Replies: 2
    Last Post: January 29th 2009, 09:05 PM
  4. roll a die
    Posted in the Advanced Statistics Forum
    Replies: 3
    Last Post: April 9th 2008, 08:35 AM
  5. Roll of the Dice
    Posted in the Statistics Forum
    Replies: 2
    Last Post: March 30th 2005, 01:40 PM

Search Tags


/mathhelpforum @mathhelpforum