I am using Office 2003 Standard, SP3

Here is the data for the linear trend:

Density 0.1 0.2 0.3
0.4 0.5 0.6
Throughput 3.125 2.726 2.378 2.061 1.742 1.452

The trendline formula displayed is y=-.3324x+3.4107

If use either SLOPE or just do a simple manual (delta y/delta x) slope
calcualtion, you get -3.324

For the 2nd order trend here is the data:

Density 0.1 0.2 0.3 0.4
Throughput 6.27 4.9 3.75 2.87

The formula displayed is y = 0.1225x^2 - 1.7475x + 7.8975. Using
another stats package I did a curve fit and got y=12.225x^2 - 17.475x
+ 7.8975, which yeilds correct ys for the given xs. Interestingly,
the 2nd order coefficient seems to be out by a factor of 100 (10^2),
while 1st order seems to be off by a factor of 10 (10^1).

Richard



On Jun 19, 11:54*am, "Jon Peltier"
wrote:
What version of Excel? Could you include the data in a follow up post (not
as an attachment), along with the coefficients you've computed?

- Jon
-------
Jon Peltier, Microsoft Excel MVP
Tutorials and Custom Solutions
Peltier Technical Services, Inc. -http://PeltierTech.com
_______

wrote in message

...



I have created trendlines for some pretty simple data using both 2nd
order polynomial and linear fits. *In both cases, the displayed
formulas have their 1st and 2nd order coefficients wrong by a factor
of 10!! (I have read lots of posts about increasing precision but this
is not what I am up against). *Has anyone seen this?- Hide quoted text -

- Show quoted text -