Results 1 to 4 of 4
Like Tree1Thanks
  • 1 Post By Wilmer

Math Help - the average of a set....

  1. #1
    Senior Member
    Joined
    Aug 2009
    Posts
    349

    the average of a set....

    ok so here is the problem....


    the average of a set of 8 consecutive odd integers is 18, what is the greatest of these integers?

    this problems seems straight forward..

    so i let x be my first integer and then counted out 7 more...

    x, x+2, x+4, x+6 and so on...

    i then added up the integers and got the setup to be

    24.75, my book says the answer is 25. which i know is an integer, but i thought my approach was right. i just took my 8 integers and divided them by 8 and set it equal to 18? how did my book get 25 and what did i do wrong?


    thanks in advance...
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    Joined
    Dec 2007
    From
    Ottawa, Canada
    Posts
    3,108
    Thanks
    68

    Re: the average of a set....

    x + (x+2) + (x+4) .... + (x+14) = 8x + 56

    (8x + 56) / 8 = 18
    8(x + 7) / 8 = 18
    x + 7 = 18
    x = 11
    So highest = x + 14 = 11 + 14 = 25

    Were you tired?
    Thanks from slapmaxwell1
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Senior Member
    Joined
    Aug 2009
    Posts
    349

    Re: the average of a set....

    yes i think i was or am a bit tired.....wow i cant believe i missed that. thanks for the correction.

    Quote Originally Posted by Wilmer View Post
    x + (x+2) + (x+4) .... + (x+14) = 8x + 56

    (8x + 56) / 8 = 18
    8(x + 7) / 8 = 18
    x + 7 = 18
    x = 11
    So highest = x + 14 = 11 + 14 = 25

    Were you tired?
    Follow Math Help Forum on Facebook and Google+

  4. #4
    MHF Contributor
    Joined
    Dec 2007
    From
    Ottawa, Canada
    Posts
    3,108
    Thanks
    68

    Re: the average of a set....

    Slow down by half, and get twice as much done...
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 5
    Last Post: May 26th 2011, 05:11 AM
  2. average
    Posted in the Algebra Forum
    Replies: 1
    Last Post: March 23rd 2010, 03:15 AM
  3. Replies: 2
    Last Post: March 13th 2010, 04:49 AM
  4. Average Value of f
    Posted in the Calculus Forum
    Replies: 4
    Last Post: January 18th 2010, 03:30 PM
  5. Average Value
    Posted in the Calculus Forum
    Replies: 1
    Last Post: May 28th 2009, 04:06 AM

Search Tags


/mathhelpforum @mathhelpforum