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I have a list of data points that I'm trying to find an equation to
To be honest, I can't remember where to begin. It's been years since I did this kind of stuff. Is there an online site that can do a good job finding an equation that accurately represents these points?

x: 6
y: 0

x: 3
y: 0

x: 2
y: 0

x: 6/4
y: -42

x: 6/5
y: -84

x: 6/6
y: -126

x: 6/7
y: -168

x: 6/8
y: -210

x: 6/9
y: -253

x: 6/10
y: -295

x: 6/11
y: -337

x: 6/12
y: -379

Thanks for any help

onassar
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1 Answers1

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Have you sketched in the points in a diagram ? Does it look like that there is a exponential relation between x and y ? In general you should try a exponential regression.

The equation is $\hat y=a\cdot e^{b\hat x}$

It can be transformed into a linear equation by taking the logarithm on both sides.

$ln(\hat y)=ln(a)+ b\hat x$

Now you can use the method of linear regresssion. There are several information in the WWW.

callculus42
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  • Thanks for the input calculus! Here it is plotted: http://i.imgur.com/q4RzNTt.png (excluding the first three; I believe the algorithm producing may be treating x values greater than or equal to 2 differently; I could be wrong though) – onassar Oct 02 '14 at 18:39
  • @onassar Maybe. I do not know what is the real relation between x and y is. The first three data points can be left out, if they do not really have a useful meaning. – callculus42 Oct 02 '14 at 19:24
  • I tried through some online calculates, but haven't had any luck. I'm running into this problem with Twitter. Here's a post where I post more information: https://twittercommunity.com/t/how-does-twitter-align-position-images-in-the-timeline/24777

    At a loss :/

     – onassar Oct 02 '14 at 19:33
  • @onassar You have to say, what you have done. Have you calculate, for example, the logarithm of the x- and y-values ? – callculus42 Oct 02 '14 at 20:06
  • @onassar The minimum of $\sum_{i=1}^n \left( ln(y_i)-ln(a)-bx_i \right)$ can be can be calculated by using the Excel solver. – callculus42 Oct 02 '14 at 20:18