Forget the book and forget the application of what you hear to the readout...for 2 reasons...
First of all, the readout is a tool for dynamics only, not frequency correction. Look at how the spectrum appears toward dynamic content and make sure that when your chourus' hit..your bass is not left out...Use the readout for dynamic frequency cohenrence, not for just looking at the curve of the mix.
Second, It is for frequency analysis..and best used for calibration before the mix begins. Extrapolation during the mix for dynamic inconsistancies is the best way to use the instrument wisely.