Cure Wounds is scaled on character level and strength. Checking quickly (with a cheated character to boost the level):
level 1, 5 strength = 20
level 1, 10 strength = 31

level 10, 5 strength = 110
level 10, 10 strength = 173

level 20, 5 strength = 210
level 20, 10 strength = 330
level 20, 15 strength = 405


First Aid heals a fixed 10%; dexterity affects the chance to apply the status (8 is 100%)