Results 1 to 4 of 4

Math Help - Couple of questions

  1. #1
    Junior Member
    Joined
    Apr 2007
    Posts
    35

    Couple of questions

    Find the best-fitting straight line to the given set of data, using the method of leasts squares. Find the correlation coefficient.
    (a)
    Best fitting line:
    Correlation coefficient:
    (b)
    Best fitting line:
    Correlation coefficient:
    (c)
    Best fitting line:
    Correlation coefficient:
    (d)
    Best fitting line:
    Correlation coefficient:








    Cost Curve: Dean (Statistical Cost Estimation, Bloomiington, Ind.: Indiana University Press, page 342) made a statistical estimation of the cost-output relationship for a shoe store. The data for the firm is given in the following table.


    4.5, 7, 9, 10, 15, 20, 33, 50 3, 3.3, 3.4, 3.5, 4.5, 5.5, 7.5, 12

    Here, is the output in thousands of pairs of shoes, and is the cost in thousands of dollars. (a) Determine the best fitting line using least squares.

    (b) Determine the best-fitting quadratic using least squares.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Forum Admin topsquark's Avatar
    Joined
    Jan 2006
    From
    Wellsville, NY
    Posts
    10,186
    Thanks
    404
    Awards
    1
    Quote Originally Posted by redraider717 View Post
    Find the best-fitting straight line to the given set of data, using the method of leasts squares. Find the correlation coefficient.
    (a)
    Best fitting line:
    Correlation coefficient:
    (b)
    Best fitting line:
    Correlation coefficient:
    (c)
    Best fitting line:
    Correlation coefficient:
    (d)
    Best fitting line:
    Correlation coefficient:
    Given the small number of points for each problem I presume you have to calculate them by hand. Look in your book for the formulas. Then you need to calculate
    \bar{x} \text{ and } \bar{y}

    \sum x_i \text{ and } \sum y_i

    \sum x_iy_i

    \sum (x_i)^2 \text{ and } \sum (y_i)^2

    Then plug these into your formulas for the slope, intercept, and correlation coefficient. It will take a little while to do this for each problem.

    -Dan
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Junior Member
    Joined
    Apr 2007
    Posts
    35
    He said we could do it with a calculator by just punching the numbers in, which is why he didn't go into great detail for these problems. Any idea how to punch them into a ti-83?
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Forum Admin topsquark's Avatar
    Joined
    Jan 2006
    From
    Wellsville, NY
    Posts
    10,186
    Thanks
    404
    Awards
    1
    Quote Originally Posted by redraider717 View Post
    He said we could do it with a calculator by just punching the numbers in, which is why he didn't go into great detail for these problems. Any idea how to punch them into a ti-83?
    I couldn't tell you that, exactly. Where's your manual for the calculator? You should be able to find instructions there. If you don't have one, try looking for it here.

    -Dan
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Need help on a couple of questions!
    Posted in the Statistics Forum
    Replies: 3
    Last Post: November 9th 2010, 11:42 PM
  2. [SOLVED] A couple questions...Help please.
    Posted in the Pre-Calculus Forum
    Replies: 2
    Last Post: July 24th 2010, 06:05 PM
  3. A couple of questions
    Posted in the Advanced Algebra Forum
    Replies: 11
    Last Post: March 1st 2010, 09:29 PM
  4. A couple of questions
    Posted in the Advanced Statistics Forum
    Replies: 9
    Last Post: October 1st 2008, 12:41 PM
  5. A couple questions..
    Posted in the Differential Geometry Forum
    Replies: 3
    Last Post: September 8th 2008, 03:37 AM

Search Tags


/mathhelpforum @mathhelpforum