Decimal Movement Speed, Slow is too slow and Fast is too fast Options

[DaklozeDuif]

Skipping the pointless introduction:
I want the player to move faster than 3:Slow but slower than 4:Fast.
Not only that, but I want a certain NPC to mover only slightly slower than the player. (about 5% or 10%)

Is it possible to set a player/event's movement speed to, for example, 3.2 or 3.5? If yes, how?

Thanks in advance.