Results 1 to 13 of 13

Math Help - Need Help in Logistic Model of Population

  1. #1
    Newbie AyuAbstractAlgebra's Avatar
    Joined
    Apr 2012
    From
    Indonesia
    Posts
    11

    Exclamation Need Help in Logistic Model of Population

    I need help in how to create logistic model of population. I have data in ten years. The model is P(t)=K/(1+L^{-Mt}) where P(t) is population in time t. K,L,M is parameters. I dont know how to find K,L,M in that problem. Please help me.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    Prove It's Avatar
    Joined
    Aug 2008
    Posts
    11,564
    Thanks
    1425

    Re: Need Help in Logistic Model of Population

    Substitute three of your data points into the equation, this will give you three equations in three unknowns to solve simultaneously
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie AyuAbstractAlgebra's Avatar
    Joined
    Apr 2012
    From
    Indonesia
    Posts
    11

    Re: Need Help in Logistic Model of Population

    Thank you so much. Now I get 3 complicated equation? Please give me some suggestion how to solve it..
    Follow Math Help Forum on Facebook and Google+

  4. #4
    MHF Contributor
    Prove It's Avatar
    Joined
    Aug 2008
    Posts
    11,564
    Thanks
    1425

    Re: Need Help in Logistic Model of Population

    Show me what you have so far...
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Newbie AyuAbstractAlgebra's Avatar
    Joined
    Apr 2012
    From
    Indonesia
    Posts
    11

    Re: Need Help in Logistic Model of Population

    I make it into 2 equation:
    first : 120.7 + (675.5*L)/e^{3M} - (554.8*L)/e^M = 0
    second : 66.5 + (675.5 *L)/e^{3M} - (609*L)/e^{2M}=0

    and I dont know what to do again
    Follow Math Help Forum on Facebook and Google+

  6. #6
    Newbie AyuAbstractAlgebra's Avatar
    Joined
    Apr 2012
    From
    Indonesia
    Posts
    11

    Re: Need Help in Logistic Model of Population

    I dont know how to use latex here, could you tell me?
    Follow Math Help Forum on Facebook and Google+

  7. #7
    MHF Contributor
    Prove It's Avatar
    Joined
    Aug 2008
    Posts
    11,564
    Thanks
    1425

    Re: Need Help in Logistic Model of Population

    How did you get these two equations?
    Follow Math Help Forum on Facebook and Google+

  8. #8
    Newbie AyuAbstractAlgebra's Avatar
    Joined
    Apr 2012
    From
    Indonesia
    Posts
    11

    Re: Need Help in Logistic Model of Population

    I substitute three of my data points into the equation, and I substitute one into two remains equation, and I get those two..
    Follow Math Help Forum on Facebook and Google+

  9. #9
    Newbie AyuAbstractAlgebra's Avatar
    Joined
    Apr 2012
    From
    Indonesia
    Posts
    11

    Re: Need Help in Logistic Model of Population

    I mean, I substitute three of my data points into the equation. From those three, I pick one and I substitute this into two remains equation, and I get those two..
    Follow Math Help Forum on Facebook and Google+

  10. #10
    MHF Contributor
    Prove It's Avatar
    Joined
    Aug 2008
    Posts
    11,564
    Thanks
    1425

    Re: Need Help in Logistic Model of Population

    Quote Originally Posted by AyuAbstractAlgebra View Post
    I mean, I substitute three of my data points into the equation. From those three, I pick one and I substitute this into two remains equation, and I get those two..
    Tell me the three equations you started with please, because your method doesn't sound right.
    Follow Math Help Forum on Facebook and Google+

  11. #11
    Newbie AyuAbstractAlgebra's Avatar
    Joined
    Apr 2012
    From
    Indonesia
    Posts
    11

    Re: Need Help in Logistic Model of Population

    Here are they:
    [LaTeX ERROR: Convert failed]
    [LaTeX ERROR: Convert failed]
    [LaTeX ERROR: Convert failed]

    And then, I substitute the 3rd to 1st and 2nd equation
    Follow Math Help Forum on Facebook and Google+

  12. #12
    Newbie AyuAbstractAlgebra's Avatar
    Joined
    Apr 2012
    From
    Indonesia
    Posts
    11

    Re: Need Help in Logistic Model of Population

    Here are they:
     K=554.8(1+\frac{L}{e^M})
     K=609(1+\frac{L}{e^{2M}})
     K=675.5(1+\frac{L}{e^{3M}})

    And then, I substitute the 3rd to 1st and 2nd equation
    Follow Math Help Forum on Facebook and Google+

  13. #13
    Senior Member
    Joined
    Jan 2008
    From
    UK
    Posts
    484
    Thanks
    65

    Re: Need Help in Logistic Model of Population

    Why only use three of the points?
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Logistic Model with Harvesting
    Posted in the Differential Equations Forum
    Replies: 1
    Last Post: April 26th 2010, 12:12 PM
  2. Insecticide, logistic model...
    Posted in the Advanced Statistics Forum
    Replies: 0
    Last Post: April 7th 2010, 06:09 AM
  3. logistic model for population
    Posted in the Differential Equations Forum
    Replies: 3
    Last Post: October 25th 2009, 06:55 AM
  4. Logistic Model with Harvesting Questions
    Posted in the Differential Equations Forum
    Replies: 1
    Last Post: September 13th 2009, 04:58 AM
  5. logistic model
    Posted in the Differential Equations Forum
    Replies: 3
    Last Post: February 12th 2009, 04:43 PM

Search Tags


/mathhelpforum @mathhelpforum