Thank you Ashish

The problem is my range of values. When I used the data directly above and
below my required value I did indeed get the same answer as you. The formula
though, used the first and last values in my table of data hence the
discrepancy as the relationship is not entirely linear through all the values.

I will keeping playing with it and see if I can solve it someo ther way.
Ideally what I want is for excel to look up the values from the table and
automatically select the values directly above and below my required answer
and interpolate as needed. As i mentioned before I have 85 rows of data and
12 columns.

Thank you for your efforts.

"Ashish Mathur" wrote:

Hi,

Assume your data above is arranged in range B5:F6. Enter 6.67 in cell B9
and use the following formula in cell C9

=TREND(C5:C6,B5:B6,B9). The answer is exactly as mentioned by you - 13817.3

--
Regards,

Ashish Mathur
Microsoft Excel MVP
www.ashishmathur.com

"hellmouthpirate" wrote in
message ...
Maybe my explanation was not the best. I have a data table that i have
incorporated into Excel. An example is:

A B C D E
6.60 13657 178.3 70.20 67.79
6.70 13886 179.9 70.16 67.68

when the answer in a cell is 6.60 or 6.70 i have used the LOOKUP function
and Excel returns all the values asspciated with that answer. I need those
values to continue with the calculation.

The problem I have now is what happens when my answer lies between 6.60
and
6.70, I need the interpolated values returned now. For example, for 6.67
the
releavnt answer from column B should be 13817.3. I would like excel to do
this automatically. I cannot write an interpolation formula as suggested
previously as there are 80 rows and 12 columns of data so it would take me
forever.

I have tried the TREND function but the answer it returns is incorrect. It
returns an answer in excess of 13886 which cannot possibly be right.


"hellmouthpirate" wrote:

I will try to explain this the best I can.

I have to do a calcualtion.
The answer to that calculation will then be used to look up data in a
table.

For Example
A B C D
6.60 13657 178.3 70.20 67.79
6.70 13886 179.9 70.16 67.68

My calculated answer was 6.67.
How do I write a formula so that excel will return the corresponding
values
for A B C & D for 6.67.

I have tried but the VLOOKUP function but it keeps returning the lower
values which is not what I want.


Yours hopefully
Simon