math problem-slightly OT

ok, I'm pretty math challenged....so here goes......I'm about ready to
start power cutting/buffing my HP-24 horiz stabilizer..............the
RPM range for my power buffer is 1000 to 3000 rpm. the rotary knob on
the power buffer is numbered from 1 to 6.

I am pretty sure that number 1 would be 1000 rpm and number 6 would be
3000 rpm. the rubbing compound and the polishing compounds require
specific rpm settings.............sooooooooo.........

my question is what rpm settings would I get from numbers 2 thru 5?

and don't tell me that I my Harbor Fraud power buffer is the
problem........

Brad