Poker help with theory

Hi! say i open 15% ep which means im defending a total 5% to a 3b. someone 3bets vs my position 3%. first part i stack w AA,KK,AKs adding 7 combos of 4bbluffs right? second and thats what troubles me do i have a calling range here? could this be the amount of his 3bbluff combos? or up to 5% its -EV to have a calling range? after that, say he 3b 9% how do i construct the calling range? that 9% is it a 9% of his positional pfr%? please help dont wanna make wrong assumptions.
thnx in advance!

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