What is the average length of a fight scene in a fantasy novel?

[2a+b(x/c)]*y/z

where:

a = elf lord casting a buffer spell

b = warrior engages a goblin

c = goblin

x = # of goblins

y = projected length of novel

z = projected # of scenes

In most cases the average length of a fight scene in a fantasy novel, as well as many other things, works out to about 6".