Is There a Simple Quantitative Technique for Projecting Values in a Series?

[AA Institute]

Hi,

Is there a general extrapolation formula (or other *simple* quantitative technique) for projecting values in a given series?

I have these numbers in a certain series sequence:

x=1, y=-3.80, x=2, y=-4.15, x=3, y=-4.47, x=4, y=-4.77, x=5, y=-5.05, x=6, y=-5.27, -5.40

Question is: does y converge to a definite final value? What is that value likely to be? I would guess somewhere around -6.0, but I want to know with more precision.

Thanks for any pointers.

AA

 

[benorin]

I know there are ploynomial interpolation thechniques, like Lagrange Interpolating Polynomials, well, just look here.

 

[mathman]

Question is: does y converge to a definite final value? What is that value likely to be? I would guess somewhere around -6.0, but I want to know with more precision.

Given this data (values of y at a discrete set of x's), there is no mathematical answer to your question. If you were to graph it, you might see some useful trend. A polynomial fit is probably a bad idea, since it will very likely give you fluctuations that are not there.