Murphy down to an equation

Here is the equation:

((U+C+I) x (10-S))/20 x A x 1/(1-sin(F/10))

Or if your rather see it this way:

(U+C+I)(10-S)       A
------------- x ----------
     20        1-sin(F/10)

So what does this mean and how to use it? Here is what each letter means:

U - Urgency
C - Complexity
I - Importance
S - Skill
F - Frequency
A - Aggravation

Each of the above is measured from a scale of 1 to 9 except A which is a constant 0.7; A was found after numerous polling to prove Murphy's Law exists. The closer it is to 10, the more likely Murphy's law will strike. So if you want a percentage, mulitply the result by 10%. Here is the equation in steps.

1) Add the Urgency, Complexity, and Importance together.
2) Take 10 and subtract your Skill.
3) Multiply (1) and (2) together then divide by 20.
4) Take the Frequency score, showing how often you do this, and divide by 10.
5) Find the sine of (4) and subtract that from 1.
6) Take (3) times 0.7 and divide by (5).

Lets use an example: me needing to go to the bathroom in a crowded room.

Urgency: extremely time sensitive, so its a 9.
Complexity: getting through without letting it out? HA! 9.
Importance: well, considering this is all I can think about, 9.
Skill: I am an introvert, for crying out loud. 3.
Frequency: Not too often, thank God! 3.

1) U+C+I = 27
2) 10-S = 7
3) 27 x 7 / 20 = 9.45
4) F/10 = 0.3
5) 1 - sin 0.3 = 0.7044
6) 9.45 x 0.7 / 0.7044 = 9.391

Hmm... very likely I will soil it, eh? 93.9% chance. I ran it through the worst case scenario and come up with approx 39. Out of a scale of 10? Wha?!? Tell me what you think of it and if it can be improved.