I'm having trouble looking up a value in my table. Here's a small
portion of my table and what i'd like to do:

15 20 25
e mph mph mph
(%) R (ft) R (ft) R (ft)
1.5 932 1640 2370
2 676 1190 1720
2.2 605 1070 1550
2.4 546 959 1400
2.6 496 872 1280
2.8 453 796 1170
3 415 730 1070
3.2 382 672 985

What i'm trying to do is lookup a speed across the top, then depending
on what speed, go down until i find my given radius, then depending on
what the radius is, slide across to the left to find out my final e%.

For example if my speed was 20 and my radius was 1070, my e% would be
2.2. But now how do i use the lookup when my speed and radius might be
different?

Any help would be greatly appreciated!!! I've tried MATCH() and HLOOKUP
() combo, but don't always know what columns to look down.

Thanks,
DK