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Math Help - Quadratic Equation for complex dataset

  1. #1
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    Quadratic Equation for complex dataset

    This is really simple for your average person but not me.

    Basically I have a dataset involving production of x amount of units and y total costs.

    I want to be able to draw a graph, produce an equation and plot the line of best fit on the graph.

    How do I find the equation for y on x?

    9, 157
    11, 215
    14, 319
    15, 358
    16, 400
    20, 592
    21, 645
    25, 885
    32, 1397
    38, 1929

    As you can tell this will produce a curvilinear graph, and from what I've determined from using a calculator, A = 18.087, B=4.66, C=1.200, although it obviously doesn't because the equation won't work.
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  2. #2
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    Re: Quadratic Equation for complex dataset

    Why won't it work?

    I get the same values giving y= 1.2007x^2+4.6627x+18.088

    You can plot it, find the line of best fit and produce this equation easily in ms-excel.
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  3. #3
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    Re: Quadratic Equation for complex dataset

    Oh dear I was using the wrong equation.

    You have a + bx + cx2

    I had... well I'm not going to tell you what I had hahaha.

    Thanks pickslides, sometimes just need some clarity, you know?

    One other thing, I'm asked out of YonX and XonY which is the correct alternative, and why? I'm not properly understanding what this is asking.. Do you?

    I realise it's YonX because in this case X is the independant variable and Y is the dependant variable but what else is there to say?
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  4. #4
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    Re: Quadratic Equation for complex dataset

    Quote Originally Posted by AmazingThicko View Post

    One other thing, I'm asked out of YonX and XonY which is the correct alternative, and why? I'm not properly understanding what this is asking.. Do you?

    I realise it's YonX because in this case X is the independant variable and Y is the dependant variable but what else is there to say?
    Thats how I would would answer it.
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