Alan,

Well, Dave Peterson actually gave a more complete response - but thanks!
Hopefully I won't disappoint.

--
Regards,
Tom Ogilvy

"Alan" wrote in message
...
Tom,

You never cease to amaze me with your capabilities.

Alan


"Tom Ogilvy" wrote in message
...
LN is called the natural logarithm. It is a logarithm using the
exponential constant (2.718. . .) as the base (see below)

the arguments for log are


LOG(number,base)

Base is optional and if left out, defaults to base 10

so Log(10,10) = 1
Log(10) = 1

but
Log(3) is Log(3,10), not base 3 and equals 0.477121254719662
Log(3,3) = 1 is the logarithm of 3 using base 3.

like wise

EXP(1) gives the exponential consant - it is the exponential constant
raised to the 1st power
http://www.mathcentre.ac.uk/students...s/resources/41

=EXP(1) = 2.71828182845905 (not 2.3)

so
=LOG(EXP(1),EXP(1)) is 1
as is
=LN(exp(1))

so LN is equal to LOG with a base of exp(1), or the match constant e


--
Regards,
Tom Ogilvy


"Joel" wrote in message
...
ln IS A FUNCTION IN EXCEL

Log is usually referes to base 10
Log(10) = 1
Log(100) = 2
Log( 1000) = 3

If we did Log for base 3
Log(3) = 1
Log(9) = 2
Log(27) = 3

LN is the Log using e as the base where e equals approximately 2.3

"dr chuck" wrote:

This is a log trendline formula from Excel semilog graphing.

y = 0.8065Ln(x) + 3.4412

can anyone tell me how the " 0.8065Ln(x) " part of this formula works?

I know y and i am solving for "x"

not sure the significance of the "Ln"

do i have to use some "log" function?

--
dr chuck