Mathematics desk
< November 20	<< Oct \| November \| Dec >>	November 22 >

Welcome to the Wikipedia Mathematics Reference Desk Archives
The page you are currently viewing is a transcluded archive page. While you can leave answers for any questions shown below, please ask new questions on one of the current reference desk pages.

November 21

Scaling percentages

Let's say that I have a number of items that have been subjected to tests: apples, oranges, bananas, etc., so that I have a failure rate for each one. Apples failed 4 out of 40 tests, so their fail rate is 10%, oranges failed 10 out of 50, so their fail rate is 20%, and so on. But let's say that, while those percentages are useful, the total number of failures - the scale of the problem - is also useful to know. The lemons may have failed 50% of the time, but there were only two tests, so the scale means that number needs to be taken into context. Now, I could simply include all the values and let people do their own figuring. With a dozen kinds of fruit, that's probably no big deal, but if you get into hundreds or thousands of items, that becomes impractical. My question really comes down to whether there's some way to combine both the scale and the rate in a meaningful way (i.e. so that exceptional items are properly highlighted)? I feel like there's a basic concept that I'm gapping on here. Matt Deres (talk) 21:13, 21 November 2019 (UTC)[reply]

x sigma range of the real failure rate given y samples and z failures? Sagittarian Milky Way (talk) 01:42, 22 November 2019 (UTC)</ref>[reply]

You usually need some sort of precise question you want to test (such as "do oranges fail more than apples?"). A good starting article would be either lady tasting tea (non-technical introduction) or p-value (technical, with links to almost every article we have on the subject). Tigraan^{Click here to contact me} 11:59, 22 November 2019 (UTC)[reply]

Thank you both. I guess I have some reading to do. :-) Matt Deres (talk) 19:46, 22 November 2019 (UTC)[reply]