Match 3 values and interpolate to find fourth

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!