An Attractive Equation

Actors must know something about something.

Dax Shepard was on Conan tonight. He commented that his face was a 6, but woman found him more attractive because his personality is a 10. He then posited that (on a scale of 1-10) women add physical attractiveness to personality, then take the average for overall attractiveness. This gives us the equation

(x+y)/2=z

Where
x = physical attractiveness
y = personality
z = total amount of attractiveness

Ex. (6+10)/2=8

I'm trying to figure out the guy equation. It'd be like

{[x²+(y/2)]/2}a=z

Where
x = physical attractiveness
y = personality
a = probability of a physical encounter
z = chance that the guy will make a move

{[6²+(8/2)]/2}1=20

Ok, so maybe it doesn't work out so well. But, what do you think of Dax's equation? I'm especially interested to hear the ladies' perspectives. And guys, what would your equation be?