Help! Table Interpolation

Have a table of data and I need to interpolate a value.  The row names are A,B,C,D and the column names have 0.5, 0.6, 0.7, 0.8 etc.  If I want to look up in that table under row B for a column value 0.67, how would I accomplish that?

Any ideas!??  Thanks!

Use'Index' and 'Match' functions. Google for more information, but this does exactly what you want.

I am becoming familiar with those functions, but am not sure how to interpolate between values for the columns.  Thoughts?

So the question is: how do you find .67 when it's between .6 and .7?

The next question is: what is the rule for interpolating the two (it the average, is it a sum, is it cacading,etc)

These questions Excel can't answer.  You will need a formula that answers that question.

Using average as an example, you can use 'roundup' or 'rounddown' to look up .6 and .7 then average the results in the formula.

Does this resolve?

If they are in sorted order, you could use HLOOKUP with exact match turned off. Check on the rules to see whether it will match the one you want.