psihokiller4 Report post Posted November 27, 2010 don't know if I may put this in general section so I'll put it in here well I think some people don't understand how % exactly works each time it's not succeeded it's more probably that it will succeed so if we have 20% in 10 tries we get 86% to succeed but it's still 80% to fail if we get 1% in 30 tries we get 25% to succeed but it's still 99% to fail note this works only till it isn't succeed than it starts from 1% again or 20%(above) this is how dynamics in reality works this calculations aren't made by PC it self but by mother nature if you try 100 times and have 1% only once in 100 times you'll succeed but you have every time 99% to fail even if you failed 120 times well I'd attach a file that I made in excel that show this % and how they work Share this post Link to post Share on other sites
ProHibited Report post Posted November 27, 2010 You really did not write that down clearly.. Simply put: Chance for a test is the same no matter how many tests you perform. (assumption of static probability, which is true when astro etc. remains constant) Share this post Link to post Share on other sites
revi Report post Posted November 27, 2010 (edited) Psiho, your post looks so wrong on so many levels, .... Just a simple point: if we get 1% in 30 tries we get 25% to succeed but it's still 99% to fail 1- in statistics/ probability studies, past events DO NOT CHANGE the chances of success and failure 2- BY DEFINITION the probabilities for two mutually exclusive events must add up to 100%. So I think you've just proven your opening statement : some people don't understand how % exactly works Edited November 27, 2010 by revi Share this post Link to post Share on other sites
RevengeKiller Report post Posted November 27, 2010 2- BY DEFINITION the probabilities for two mutually exclusive events must add up to 100%. Not true. You're confusing mutually exclusive events with collectively exhaustive events. So I think you've just proven your opening statement : some people don't understand how % exactly works Share this post Link to post Share on other sites
Raz Report post Posted November 27, 2010 (edited) 2- BY DEFINITION the probabilities for two mutually exclusive events must add up to 100%. Not true. You're confusing mutually exclusive events with collectively exhaustive events. So I think you've just proven your opening statement : some people don't understand how % exactly works You either succeed or fail according to the original post... 25% to succeed, 99% to fail. The two are mutually exclusive... therefore must add to 100. Each chance is 1% success, 99% fail. The total probability of success/fail over 30 iterations may well be 25% success - but the fail would be 75%! Edited November 27, 2010 by Raz Share this post Link to post Share on other sites
RevengeKiller Report post Posted November 27, 2010 2- BY DEFINITION the probabilities for two mutually exclusive events must add up to 100%. Not true. You're confusing mutually exclusive events with collectively exhaustive events. So I think you've just proven your opening statement : some people don't understand how % exactly works You either succeed or fail according to the original post... 25% to succeed, 99% to fail. The two are mutually exclusive... therefore must add to 100. Each chance is 1% success, 99% fail. The total probability of success/fail over 30 iterations may well be 25% success - but the fail would be 75%! Eh, it's getting petty but the statement which I said wasn't true - isn't. Given the premise that there are only two potential events then yes, the probability of either of those two collectively exhaustive events occurring, (which also happen to be mutually exclusive), would of course add up to 100% given of course that an event transpires. However, the fact that they are mutually exclusive in no way dictates their collective likelihood of occurring. Revi's statement was an isolated assessment of the rules of probability which is simply incorrect. Cheers Share this post Link to post Share on other sites
revi Report post Posted November 27, 2010 ... Revi's statement was an isolated assessment of the rules of probability which is simply incorrect. ... I agree, sloppy formulation. For the general case, you are right. In this particular case of success/failure (one of which has to occur), the difference is academic Thanks for the correction and clarification Share this post Link to post Share on other sites
RevengeKiller Report post Posted November 27, 2010 I agree, sloppy formulation. For the general case, you are right. In this particular case of success/failure (one of which has to occur), the difference is academic Thanks for the correction and clarification You've got class. I see you training again I leave you be kk Share this post Link to post Share on other sites
Kaddy Report post Posted November 27, 2010 Even tho the rate is %1, the sample of 100 doesnt have to have exactly 1 fail. They're called standart deviations and variances, which I'm studying right now Share this post Link to post Share on other sites
