What are the requirements for a pokemon's stat to achieve its maximum??

Question

If i had an adamant rampardos that was max EV (252) trained in attack, but only 28 IVs in attack, could it's attack stat still achieve its maximum?

Do you need a beneficial nature, and perfect IVs in that stat, and max EV trained in that stat in order to get the stat to its maximum?

Answer 1

yes you need a beneficial nature, perfect IV's and 252 evs to achieve the maximum

Answer 2

a Beneficial Nature so it can boost attack stats.