I am a bit confused by pressure altitude, in my ground school we were taught and equation ((29.92 - altimeter setting)*1000)+ altitude) is equal to something.
I believe that something to be pressure altitude. What I don't know is how some of the numbers are acquired. Is the altimeter setting just an arbitrary number that you plug in or is it the number that you get from ATIS. Then for the addition of altitude, is that the true altitude or the altitude measurement fed form the "arbitrary" pressure given to the altimeter?