Results 1 to 3 of 3

Math Help - Data question to find missing variables

  1. #1
    Member
    Joined
    Mar 2009
    Posts
    97

    Data question to find missing variables

    The table shows the weights of 100 children in class 1.
    An estimate of the mean weight of the children is calculated as 44 kg.
    Calculate the values of a and b.

    w (kg) Frequency
    20 < w <30 12
    30 < w < 40 21
    40 < w < 50 38
    50 < w < 60 a
    60 < w < 70 b



    Answer a = ........................... , b = ...........................

    ps last < should be greater OR equal to

    How do I go about starting the problem?
    Regards
    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 200001 View Post
    The table shows the weights of 100 children in class 1.

    An estimate of the mean weight of the children is calculated as 44 kg.
    Calculate the values of a and b.

    w (kg) Frequency
    20 < w <30 12
    30 < w < 40 21
    40 < w < 50 38
    50 < w < 60 a
    60 < w < 70 b



    Answer a = ........................... , b = ...........................

    ps last < should be greater OR equal to

    How do I go about starting the problem?

    Regards
    12 + 21 + 38 + a + b = 100 .... (1)


    \frac{12 \times 25 + 21 \times 35 + 38 \times 45  + a \times 55 + b \times 65}{100} = 44 .... (2)

    Solve equations (1) and (2) simultaneously.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Member
    Joined
    Mar 2009
    Posts
    97
    Thats great. Thanks
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Estimating Missing Data
    Posted in the Statistics Forum
    Replies: 0
    Last Post: March 6th 2012, 11:43 PM
  2. Missing data - biased sampling
    Posted in the Advanced Statistics Forum
    Replies: 0
    Last Post: November 10th 2010, 03:12 AM
  3. interpretation of missing data imputation
    Posted in the Advanced Statistics Forum
    Replies: 0
    Last Post: June 2nd 2009, 12:18 AM
  4. Test yourself Find the missing data.
    Posted in the Trigonometry Forum
    Replies: 5
    Last Post: August 31st 2008, 10:46 AM
  5. Replies: 0
    Last Post: November 6th 2007, 11:48 PM

Search Tags


/mathhelpforum @mathhelpforum