Match 3 values and interpolate to find fourth

**nate1** · 05-07-2013, 12:37 PM

I have a data set with 4 columns of data. I wish to match the first three columns and output the fourth if all previous values match. To complicate matters, I would like to interpolate the fourth value based on the third value. The attached sample shows a bit more detail.

I have tried matching multiple columns in an array with some success, but I cannot quite get what I am looking for.

Thanks in advance to anyone who has an idea of how to solve this!

**martindwilson** · 05-07-2013, 12:54 PM

trouble is 2 fold first for match with a criteria of 1 to work data must be sorted ascending put in e2 =a2&b2&c2 fill down then sort by col e youll see the diference
secondly i cant see why first result should be 0.253 as there is an exact match for 5 2 350
in row 18
lastly
you can use the non array
=INDEX($D$2:$D$109,MATCH(F2&G2&H2,INDEX($A$2:$A$109&$B$2:$B$109&$C$2:$C$109,0),1))
and since youll need to sort the data by whats in col e you could use
=INDEX($D$2:$D$109,MATCH(F2&G2&H2,E2:E109),1)

**nate1** · 05-09-2013, 05:06 PM

I think I can answer the second discrepancy. I had originally used 360 which provided an interpolated result of 0.253, and I forgot to change it back. I followed your first recommendation and was able to use this code to get what I wanted. I have a large dataset, so a non array solution worked out favorably. Thank you for the help!