Google Answers Logo
View Question
Q: Microsoft Excel Trendline Equation is incorrect. Just plain wrong. ( No Answer,   1 Comment )
Subject: Microsoft Excel Trendline Equation is incorrect. Just plain wrong.
Category: Computers > Software
Asked by: mrbluesummers-ga
List Price: $5.00
Posted: 25 Sep 2006 19:10 PDT
Expires: 26 Sep 2006 10:52 PDT
Question ID: 768410

The fact is I'm running a regression between two sets of data: Size
and Decay.  From my data points, you can see that the larger the
object, the "lower" the decay is.  I've punched the numbers into excel
and it's given me a nice looking trendline (POWER), but it refuses to
give me a decent equation.

What I've tried:
I tried typing various mutations of the equation (parenthases,
different methods of inputting it into a cell, etc)

I've tried transforming the function, but I can't do too much of that by hand.

You can see the Excel file at

In case the link goes down; here's the data...
EQN: 14.090504x^-1.06355736
Size	Decay	Power(WRONG)
6.18014	18	2.030740615
12.3603	5.95	0.971607902
24.7206	3.93	0.464866627
49.4411	2.97	0.222416311
98.8823	2.4	0.106415159
197.765	1.97	0.050914314
395.529	1.73	0.024360062
791.058	1.52	0.011655092
1582.12	1.36	0.005576374
3164.23	1.23	0.00266803
6328.47	1.14	0.001276519
12656.9	1.03	0.000610754
25313.9	0.95	0.000292214
50627.7	0.88	0.000139811
101255	0.82	6.68927E-05
202511	0.785	3.20047E-05

Request for Question Clarification by efn-ga on 25 Sep 2006 23:19 PDT
What is your question?  Are you looking for an equation, or a way to
get an equation out of Excel, or something else?  Have you tried the
LOGEST function?
There is no answer at this time.

Subject: Re: Microsoft Excel Trendline Equation is incorrect. Just plain wrong.
From: bcattwood-ga on 26 Sep 2006 08:02 PDT
It is because you are using the wrong chart type.  Change it from line
to XY (scatter) and that should fix your problem.  Please mail me the

Important Disclaimer: Answers and comments provided on Google Answers are general information, and are not intended to substitute for informed professional medical, psychiatric, psychological, tax, legal, investment, accounting, or other professional advice. Google does not endorse, and expressly disclaims liability for any product, manufacturer, distributor, service or service provider mentioned or any opinion expressed in answers or comments. Please read carefully the Google Answers Terms of Service.

If you feel that you have found inappropriate content, please let us know by emailing us at with the question ID listed above. Thank you.
Search Google Answers for
Google Answers  

Google Home - Answers FAQ - Terms of Service - Privacy Policy