Logarithmic curve formulas in charts and LOGEST fx values?

(Preface: I am not a math genius so I may be doing something way wrong)

I am trying to calculate values for a curve using the LOGEST fx, but the
numbers are not agreeing with the formula provided by the logarithmic curve
formulas in a chart of the data (nor by the 'eyeball' method). Any thoughts?

Hi Rich,

How could we possibly know if you don't give us:

Values input to the formulas,
The formulas,
The results of the formulas,
What you expected,
What the eyeball expectations were
?

--
Kind regards,

Niek Otten

"Rich" <Rich@discussions.microsoft.com> wrote in message
news:43EE9057-168E-45C1-8A88-CB40127161DB@microsoft.com...
> (Preface: I am not a math genius so I may be doing something way wrong)
>
> I am trying to calculate values for a curve using the LOGEST fx, but the
> numbers are not agreeing with the formula provided by the logarithmic
> curve
> formulas in a chart of the data (nor by the 'eyeball' method). Any
> thoughts?

Don't hesitate to post again (in this same thread) with some more details

--
Kind regards,

Niek Otten

"Niek Otten" <nicolaus@xs4all.nl> wrote in message
news:u3QLXqr7FHA.3044@TK2MSFTNGP10.phx.gbl...
> Hi Rich,
>
> How could we possibly know if you don't give us:
>
> Values input to the formulas,
> The formulas,
> The results of the formulas,
> What you expected,
> What the eyeball expectations were
> ?
>
> --
> Kind regards,
>
> Niek Otten
>
> "Rich" <Rich@discussions.microsoft.com> wrote in message
> news:43EE9057-168E-45C1-8A88-CB40127161DB@microsoft.com...
>> (Preface: I am not a math genius so I may be doing something way wrong)
>>
>> I am trying to calculate values for a curve using the LOGEST fx, but the
>> numbers are not agreeing with the formula provided by the logarithmic
>> curve
>> formulas in a chart of the data (nor by the 'eyeball' method). Any
>> thoughts?
>
>

Rich -

> I am trying to calculate values for a curve using the LOGEST fx, but the
> numbers are not agreeing with the formula provided by the logarithmic
> curve formulas in a chart of the data (nor by the 'eyeball' method). Any
> thoughts? <

Two thoughts:

(1) LOGEST is appropriate for an exponential trendline, not for the
logarithmic trendline.

(2) Be sure you're using an XY (Scatter) chart type, not a Line chart type.

- Mike
www.mikemiddleton.com

http://groups.google.com/group/micro...d0f2172c25a661

Jerry

Rich wrote:

> (Preface: I am not a math genius so I may be doing something way wrong)
>
> I am trying to calculate values for a curve using the LOGEST fx, but the
> numbers are not agreeing with the formula provided by the logarithmic curve
> formulas in a chart of the data (nor by the 'eyeball' method). Any thoughts?