WikiHow has an article suggesting a method for making decisions quantitatively. It reminds me a bit of my excel decision making algorithm.

How to Make a Decision Using a Quantitative Scoring System - WikiHow

1. Write the question you’re trying to decide, e.g. "Which car should I buy?"
2. Write up to five must-have qualities (e.g. Mileage, style, size, etc.) using too few qualities will not provide an accurate depiction of the item. If you have more than five qualities, the value of the score can get diluted, so think hard about what really matters to you. Leave the nice-to-have qualities aside, or you might get distracted and make a decision based on unimportant factors. Make sure the qualities are non-overlapping (e.g., mileage, purchase price, expected resale value, and reliability are all "cost of ownership" issues) otherwise you essentially double-count the same underlying attribute.
3. Rate the importance of each of these qualities on a scale of 1 to 10 in terms of how important each is to you (e.g. if reliability is far more important than anything, it gets a 10, if mileage is the second most important but really not nearly as important as reliability you might give it a 5 or 6, and so on).
4. List your options (e.g. Nissan Sentra, VW Jetta, etc.).
5. Provide a score on a scale of 1 to 10 for each quality you put down for that option. Do this for all options you put down (e.g. if the Sentra gets 25 MPG, and you think that is pretty good, give it a 7, and if a hybrid gets 35 MPG, give it a 9). This is a subjective scale, so it’s up to you to score it as honestly as possible to make the best decision by the end of this.
6. Compute scores for each option by multiplying the quality score you gave your option with your target quality score, the one you created in Step 3 (e.g. Nissan Sentra’s MPG rating is 56: 8 [the importance of good MPG, to you] x 7 [how well you think this car rates in that area]). Do this for all qualities listed in all your separate options.
7. Sum up the scores for each quality for a total score for that option. Do this separately for all options you listed.
8. Compute the "perfect score" by creating an option that gets all tens.
9. Divide each option’s total score by the "perfect score" and multiply by 100 to give you a simple 1-100% total. The option with the highest percentile score (compared to perfection) is your best choice.

However, by the time you go through all these steps, you may have been killed by a bear.