Results 1 to 5 of 5

Math Help - tossing a fair coin

  1. #1
    Newbie
    Joined
    May 2010
    Posts
    11

    tossing a fair coin

    Suppose that a fair coin is tossed repeatedly until a head is obtained for the first time.

    (a) What is the expected number of tosses that will be required?
    (b) What is the expected number of tails that will be obtained before the first head is
    obtained?

    does anyone know how to do this one????
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Flow Master
    mr fantastic's Avatar
    Joined
    Dec 2007
    From
    Zeitgeist
    Posts
    16,948
    Thanks
    5
    Quote Originally Posted by uva123 View Post
    Suppose that a fair coin is tossed repeatedly until a head is obtained for the first time.

    (a) What is the expected number of tosses that will be required?
    (b) What is the expected number of tails that will be obtained before the first head is
    obtained?

    does anyone know how to do this one????
    The answer to (b) is one less than the answer to (a). Review the geometric distribution to get the answer to (a).
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    May 2010
    Posts
    11
    i found E(x) in (a) to equal 2 and so (b) would equal 1 but i wasnt sure that was correct. is that what you found?
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Flow Master
    mr fantastic's Avatar
    Joined
    Dec 2007
    From
    Zeitgeist
    Posts
    16,948
    Thanks
    5
    Quote Originally Posted by uva123 View Post
    i found E(x) in (a) to equal 2 and so (b) would equal 1 but i wasnt sure that was correct. is that what you found?
    Yes.
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Newbie
    Joined
    May 2010
    Posts
    11
    thanks for all your help!!
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. coin tossing
    Posted in the Advanced Statistics Forum
    Replies: 1
    Last Post: November 22nd 2010, 08:55 AM
  2. Replies: 1
    Last Post: March 8th 2010, 11:32 PM
  3. Replies: 0
    Last Post: March 8th 2010, 10:15 PM
  4. coin tossing
    Posted in the Statistics Forum
    Replies: 8
    Last Post: January 30th 2010, 02:08 PM
  5. When is a fair coin toss not fair?
    Posted in the Advanced Statistics Forum
    Replies: 3
    Last Post: November 12th 2008, 07:48 AM

Search Tags


/mathhelpforum @mathhelpforum