Q:

dynamic score value from right/wrong ratio

Hopefully this will make sense. I'm writing an quiz type game where players select a question, attempt an answer, if correct score value is added to player, otherwise take value from players score. I've got all that working, now I'm curious to see if it makes sense and is do-able to dynamically adjust the value of a question based on its right/wrong ratio.
Consider the table below. Each question has a value from 100-1000 in 100 point increments.

| ID | numbRight | numWrong | Score |
|----|-----------|----------|-------|
| 1  |    30     |    30    |  100  |
|----|-----------|----------|-------|
| 2  |    40     |    60    |  200  |
|----|-----------|----------|-------|
.....................................
| 10 |    80     |    20    |  1000 |
|----|-----------|----------|-------|

as you can see question 1 has a ratio of 1/1 is it's probably ok where it is. 
Looking at question 2 we see that it has a ratio of 2/3. This question is more often answered incorrectly then it is correctly. This question might need to be assigned a higher value. 
Skipping the next few questions, we see that question 10 has a ratio of 4/1. This question is the opposite of question 2. It probably should be moved down. We don't want to be giving players a high value question when clearly it is not difficult to the average person.
The constraint is this: 

each question must have a value between 100-1000 and in 100 point increments. 
There must be a question in each place. So there must be a question with a value of 100 all the way to 1000, for a total of 10 questions.

Questions 

Is there a formula that could be applied to this? 
Could it be pragmatically decided that those questions should be moved up or down? 
If 10 is moved down because of its ratio, causing 9 to become 10. However at the next pass the formula would determine that the now 10 needs to be moved back down because of its own ratio. How do I avoid an endless loop?

side notes: There are more then 10 questions in the full program however only questions in one category will be consider for this formula at the same time. Secondly, the stats are all made up, just thought it would be easier this way.

A:

The trouble is, if lots of people get a question wrong, you don't know whether it's because it's a hard question (which is what you want), or because it's a bad question (poorly worded, misleading, or maybe even with the wrong answer marked as "right").
Standardized tests, like the GRE, put new questions on the test alongside old questions, to make sure that the kinds of people who get them right are also the kinds of people who got good scores with the old questions. If you don't have something similar, then I'd hesitate to trust any automatic ranking algorithm.
So if you want to proceed with this, you'll need, at a minimum, some automated way to figure out the difference between hard questions and good questions. That's going beyond programming, and more into math and statistics. I don't pretend to be an expert in either subject, but here are a few things that you might find interesting:

The Princeton Review's "Cracking the GRE" books explain how the GRE field-tests new questions. (Or at least they did several years ago, before the GRE went completely over to computerized adaptive testing. If newer editions turn out not to be helpful, see if you can find some older editions.) The Princeton Review GRE Web site might also have some useful information.
Wikipedia has articles on computerized adaptive testing and regression analysis that might be useful.
Also check out the mathematics StackExchange and the statistics StackExchange.

