Horizontal asymptote

[Chookz]

Hi experts,
I have graphed the following values in a scatter chart (columns separated by comma):

Time, Power
14.6, 900
78.4, 726
350.6, 520
1148.3, 399

Plotting time on the x-axis and Power on the y-axis.
I want to know the power asymptote or the horizontal asymptote, and have no idea how to do this. Is this possible in excel?
Any help would be much appreciated.
(Please note my mathematical theory isn't great, so don't get too technical)
Thanks in advance

 

[JoeMo]

Hi experts,
I have graphed the following values in a scatter chart (columns separated by comma):

Time, Power
14.6, 900
78.4, 726
350.6, 520
1148.3, 399

Plotting time on the x-axis and Power on the y-axis.
I want to know the power asymptote or the horizontal asymptote, and have no idea how to do this. Is this possible in excel?
Any help would be much appreciated.
(Please note my mathematical theory isn't great, so don't get too technical)
Thanks in advance

If you click on your chart's data series and go to Chart/Layout/Trendline/More Trendline Options/Power and tick the box Display Equation on the Chart you will see the Power law equation that describes your data.

Using the data you posted I get Power = 1553.7t^-0.189. The fit is very good with an R^2 value of 0.9832.

You can now generate more data by entering increasing times and the estimated Power using this equation. If you do that you can quickly convince yourself that there is no asymptote. In fact, a power law of the form f(t) = ct^a where c and a are constants and real numbers generally has no asymptote. In your case with c>0 and a < 0, the function decreases monotonically as t tends to infinity.