A little help on AGA3 lenghts tables comprehension

[VitorBart]

Hello everyone.

I need some help to understand these tables from AGA3:



Question is: whenever I find my self in a situation where BETA is not a round number (suppose BETA = 0.45) which line should I use as referral? The line with BETA = 0.40 or the line with BETA = 0.50? Is there any reference about this specific matter?

Thanks!

[VitorBart]

This really sucks* not even Google can help me out with this one. ACK.