Results 1 to 3 of 3

Math Help - Mean and median.

  1. #1
    Junior Member
    Joined
    Aug 2010
    Posts
    25

    Mean and median.

    A set of seven different positive intergers has mean and median both equal to 20. what is the largest possible value this set can contain?
    Last edited by mr fantastic; August 23rd 2010 at 02:21 AM. Reason: Re-titled.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Newbie
    Joined
    Aug 2010
    Posts
    21
    Quote Originally Posted by rai2003 View Post
    A set of seven different positive intergers has mean and median both equal to 20. what is the largest possible value this set can contain?
    You know what the 4th value has to be 20.
    So you have __,__,__,20,__,__,__
    Fill the first 3 numbers with the smallest 3 positive integers (1,2,3)
    now you have 1,2,3,20,__,__,__
    fill the next to numbers after 20 with 21 and 22
    1,2,3,20,21,22,x
    Since the average formula is \frac{sum of elements}{number of elements},
    put what you know into the formula: \frac{69+x}{7}
    Calculate the maximum value by multiplying 7 by 20 and subtracting 69:
    (7*20)-69=71
    Answer: 71
    verify: \frac{1+2+3+20+21+22+71}{7} = 120 (120 is max value for equation, calculate by 7*20
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Junior Member
    Joined
    Aug 2010
    Posts
    25
    thanks
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Mean and median.
    Posted in the Statistics Forum
    Replies: 1
    Last Post: September 29th 2011, 09:07 PM
  2. Median
    Posted in the Statistics Forum
    Replies: 4
    Last Post: July 5th 2010, 07:21 PM
  3. The Median
    Posted in the Statistics Forum
    Replies: 1
    Last Post: December 4th 2009, 12:21 PM
  4. Mean and Median
    Posted in the Statistics Forum
    Replies: 7
    Last Post: July 25th 2009, 05:52 AM
  5. What does the median tell us?
    Posted in the Advanced Statistics Forum
    Replies: 1
    Last Post: April 15th 2008, 08:56 AM

Search Tags


/mathhelpforum @mathhelpforum