% Total Damage and % Attack

I'm not really good at Math so I don't know how to calculate these two % bonuses. Let's say you set all variables equal in the damage range formula for say, a Corsair. Which would yield a larger effect on total damage, 4% Total Damage or 8% Attack?

Since % Attack is dependent on total Weapon Attack while % Total Damage is an outside multiplier, apparently, do I need to list my stats or is it possible to calculate the previous question without my stats?