Can you help me to solve the below equation in excel ?

[K Lee]

Can you help me to solve the below equation in excel ?
Y= 3494e0.012x and Y=10,000, therefore,
10000=3949e0.012x,
I like to find out the value of x,
please also list the equation so that I can input in excel by myself work
out other numbers.
Thanks.

 

[Rick Rothstein]

Your are going to have to clarify your expressions for us. A number
presented with e-notation does not permit a fractional value after the "e".
Is the number in your Y=3494e0.012x expression actually supposed to be
3494*10^0.012 where I have used ^ to indicate raising a number (10 being
assumed in this case) to a (fractional or whole number) power? To guide you
a little bit... assuming your 3494e0.012 is in fact a number, then your
expression is Y=Nx (where N stands for any number) and solving for 'x'
merely requires you to divide both sides by N to isolate 'x' by itself. So,
x=Y/N which, using your original presentation, would be x=10000/3494e0.012
and, once you resolve the 3494e0.012 presentation problem, is a simple
division problem. To reiterate.... Excel (and almost any other software)
will not recognize 3494e0.012 as a valid number, but it will recognize
3494*10^0.012 as being a valid number. In Excel, if A1 contains your 10000
value (no thousands separators are used when entering a number in Excel) and
B1 contains 3494*10^0.012, then putting =A1/B1 in C1 (or any other cell)
will generate the answer you want.

 

[Dana DeLouis]

Can you help me to solve the below equation in excel ?
Y= 3494e0.012x and Y=10,000, therefore,
10000=3949e0.012x,
I like to find out the value of x,
please also list the equation so that I can input in excel by myself work
out other numbers.
Thanks.

Hi. (Note that you used both 3494 and 3949)

x = Ln(10000/3949) / 0.012

 

[Rick Rothstein]

I just read Dana's reply and now realize you meant "e" as the exponential
constant and not an e-notation representation. Sorry for any confusion my
previous response may have caused you.

 

[Dana DeLouis]

Hi. (Note that you used both 3494 and 3949)

x = Ln(10000/3949) / 0.012

Rick made a good point. I was assuming...

10000 = 3949*Exp(0.012*x)

- - -
Dana DeLouis

 

[Rick Rothstein]

Can you help me to solve the below equation in excel ? Y= 3494e0.012x

Rick made a good point. I was assuming...

10000 = 3949*Exp(0.012*x)

LOL... actually, I think you made the good point... I am pretty sure your
reading of the message was the correct one.

 

[joeu2004]

Can you help me to solve the below equation in excel ?
Y= 3494e0.012x and Y=10,000, therefore,
10000=3949e0.012x,
I like to find out the value of x

I wonder if "e" is the mathematical constant (aka Euler's number), and
you meant to write:

Y = 3494*e^(0.012*x)

In that case, we really should require that you complete the algebraic
transformation yourself, but what the heck ....

ln(Y / 3494) = 0.012 * x

x = ln(Y / 3494) / 0.012

In Excel, if Y (10000) is in A1, in A2 you would write the formula:

=ln(A1 / 3494) / 0.012

As a double-check, in A3 you might write:

=3494 * exp(1) ^ (0.012 * A2)

We expect __about__ 10000. The result might not be exact because of
the many approximations and the artifacts of binary computer
arithmetic.

 

[K Lee]

Thanks guys.

A quick background. I get a trendline and select the exponential function.
It comes up with a formular i.e.
y = 3949.4 e "superscript" 0.012x
I have the y number = 10,000
I used your formular
Log (10,000/3949.4)/0.012 and get the number of 35.08, however, I understand
I shall get a number close to 80. Am I putting the wrong formular?

Thanks

 

[Shane Devenshire]

Hi,

You should be using

=LN(10000/3949.4)/0.012

~77.4185

If this helps, please click the Yes button

Cheers,
Shane Devenshire

 

[Rick Rothstein]

But you didn't use joeu2004's formula... you changed his LN function to a
LOG function which, in Excel, defaults to a LOG10 function call when you
don't specify the optional base argument. On top of that, you cannot include
commas (thousands separators) in your numbers. Try this and it should work
for you...

=LN(10000/3949.4)/0.012

 

[joeu2004]

I used your formular
Log (10,000/3949.4)/0.012 and get the number of 35.08,
however, I understand I shall get a number close to 80.
Am I putting the wrong formular?

As others noted, you should use the LN() function, not the LOG()
function.

Also, in your original posting, I notice now that you wrote 3494 in
formula and 3949 in another. Now you are using 3949.4. Obviously,
use whatever is right. FYI, you can change the precision (number of
decimal places) of the constant factors in the treadline formula.