Is it better to use "i" or "?" for tooltip/help content on mobile
Info Icon vs Question Mark
How to calculate a confidence interval for estimating a proportion when the population is very small? I plan to execute a little study on whether dentists tend to grant privately insured patients (PRIV) a sooner appointment compared with publicly insured patients (PUB). I want to restrict this study to the dentists of a single town in Germany.  In this town there are about 500 dental practices and I am willing to call maximum 100 practices (twice, once as a PUB and once as PRIV). (A sample without replacement of size up to 100)  So the result of this examination would be a list of up to 100 practices with an associated value of 1 - if the appointment for the PRIV was more than two days sooner - and a 0 - if not. The proportion of 1s is what I want to estimate.  Now the sources I have been reading always assumed a much larger population with a finite population correction close to 1. This is why I doubt that blindly using a conservative or approximate confidence interval would lead to a statistically meaningful result.   So my first question is, of course, whether it is reasonable at all trying to estimate the proportion using a confidence interval in this case? And if yes, then what statistical technology/method (leading to a CI) would be a good choice for this use case?   One idea that comes to mind is using a sample size of 25 f.x., in that case the FPC would be 0.95 - "close enough" to 1. But it seems stupid trying to improve the quality of an estimation by reducing the information used for the estimation. Is it possible to change the linkage of Nether portals? I am having a serious trouble finding an agreement between the two facts in Special Relativity:  (1) given two events $A$ and $B$ in spacetime separeted by a spacelike interval $s$, the distance in space between the two events will be the shortest in the reference frame which the two events occur simultaneously:   The invariance of the interval says $s^2=(\Delta x)^2-(c\Delta t)^2$ and $\Delta x$ is minimum when $\Delta t=0$  (2) the length contraction says $L=\dfrac{L_0}{\gamma}$ where $\gamma=(1-(v/c)^2)^{-1/2}$ , $L_0$ is the proper length of an object in a reference frame which the object is at rest and $L$ is the length of the object in a reference frame which the object moves with speed $v$ in the $x$ direction.  This says that the lenght of the object in the $x$ direction is the largest in the comoving reference frame of this object.  The question is: According to (1), the reference frame in which two events $A$ and $B$ occur simultaneously is the reference frame that gives the shortest distance in space between the two events. Let $A$ and $B$ be the two end points of a meter stick in a reference frame in which the stick is at rest and at time $t=0$. This two events occur simultaneously, so the distance in space between the two is the shortest acording to (1). But according to (2) shouldn't this distance be the largest?  What is wrong? Why does evolution not make life longer for humans or any other species?  Wouldn't evolution favour a long life? Symmetrical twin paradox in a closed universe Take the following gedankenexperiment in which two astronauts meet each other again and again in a perfectly symmetrical setting - a hyperspherical (3-manifold) universe in which the 3 dimensions are curved into the 4. dimension so that they can travel without acceleration in straight opposite directions and yet meet each other time after time.  On the one hand this situation is perfectly symmetrical - even in terms of homotopy and winding number. On the other hand the Lorentz invariance should break down according to , so that one frame is preferred - but which one?  So the question is: Who will be older? And why?  And even if there is one prefered inertial frame - the frame of the other astronaut should be identical with respect to all relevant parameters so that both get older at the same rate. Which again seems to be a violation of SRT in which the other twin seems to be getting older faster/slower...  How should one find out what the preferred frame is when everything is symmetrical - even in terms of GRT?  And if we are back to a situation with a preferred frame: what is the difference to the classical Galilean transform? Don't we get all the problems back that seemed to be solved by RT - e.g. the speed limit of light, because if there was a preferred frame you should be allowed to classically add velocities and therefore also get speeds bigger than c ?!? (I know  is only a local theory but I don't understand why the global preferred frame should not 'override' the local one).  Could anyone please enlighten me (please in a not too technical way because otherwise I wouldn't understand!)  EDIT Because there are still things that are unclear to me I posted a follow-up question: Do strong and weak interactions have classical force fields as their limits? Electromagnetic interaction has classical electromagnetism as its classical limit. Is it possible to similarly describe strong and weak interactions classically? I have data with a column containing a number value, and I want to divide the value of each feature by the total sum of all the values in the column (to get a percentage).  So I would like to know if there is some simple syntax in the QGIS field calculator to get the sum of a column, preferably without resorting to for loops and what not.    I have a shapefile where feature A has the value X in column B. How can I summerize the values for all features in column B in order to divide value X to get a percentage for each feature? Is there an idiom for someone who gets what he deserved? Like someone receiving punishment for his evil deeds or someone getting awarded for his good deeds? I realize this is probably going to come off as a bit silly, but in Iron Man II how could James Rhodes easily don the Mark II armor that was designed to fit Tony Stark?  As you can see in this image (which isn't an "in universe" shot) Tony and Rhodey are roughly the same height, but it appears that Rhodey has a smaller frame than Tony, which would seem to make for an ill fit of the armor, especially for flight.  This issue could of course have been addressed by the Air Force during the retrofit with Justin Hammer. Converge or diverge? : $\sum_{n=1}^{\infty}\frac{\tan{n}}{2^{n}}$ I would like to make cross references to own defined counter on environments. So far I have tried the following,   \documentclass{book} \newcounter{entryc}[subsection] \newcommand{\thetheorem}{\thesubsection.\arabic{entryc}} \newenvironment{qd}[1]{\refstepcounter{entryc}\noindent\textbf{Quasi Definition \thetheorem.}\begin{itshape}} {\end{itshape}} % \begin{document}  \chapter{First chapter} This is the first chapter.  \section{First section} This is the first section.  \subsection{First subsection} This is the first subsection.  \begin{qd}{}\label{qd:emp} This is my environment. \end{qd}  \noindent In quasi definition \ref{qd:emp} it \dots  \end{document}   What happens is that     But I would prefer "...In quasi definition 1.1.1.1". Do anyone have some suggestions of how solve this? and How to avoid the          \noindent  thing before the continuation of the text?   Additional information: if possible I would try to not use ntheorem. Recursively delete empty directories in Windows I have a directory on my Windows 7 machine that has hundreds if not thousands of sub-directories.  Some of them have files, some do not.  I want to delete all the empty directories.  Looking at the del and rmdir DOS command, it does not look like you can recursively do this without deleting all the files.  Is there a way to do this from the command line? There are two 9-digit numbers on the back of the Global Entry card. The one on the upper left corner is the Known Traveler Number or PASSID. But on the upper right hand corner there is another 9-digit number, slightly larger than the PASSID. What is the purpose of this second 9-digit number? I know there a lot of posts about ram but I'm still confused about it. I'm building a new system and because it was cheaper, I bought a 6GB kit from Corsair. So I'm wondering if I would be better off just using 4GB of it in a dual channel configuration or just add all 6GB (3 DIMMS) in a single channel configuration.   Thanks Are "beginner questions" allowed on Stack Overflow? I noticed that  (about basic  syntax) received a lot of downvotes as soon as I posted it. Is there any specific policy against the posting of questions with "obvious" answers on Stack Overflow?  I'm unclear as to why questions with "obvious" answers aren't usually well-received by the community - are beginner questions considered harmful for some reason? ("Obvious" is a relative term, of course - this type of question would be helpful to anyone who was learning C# for the first time, but it wouldn't be helpful to an experienced C# developer.) I have just bought a new bike and had it about a month now. I don't really know much about bikes but I do know how to repair an inner tube.  I have had one puncture and just bought a new inner tube. It worked for a few days and then went down again so this time I got a puncture repair kit. I took the inner tube out to check for any punctures and found nothing. I put it in water and pumped it up and there were no bubbles. I went around the entire tube pushing it next to my ear and heard nothing. I checked the tire to see if anything was wrong - there was nothing that I could see.   So I put it all back together and took it for a ride and got about half a mile and the tire was flat. I pumped it up and got about another half a mile and it was flat again.  Do you have any suggestions for me? Suppose I have a 6 GB page file on an SSD and another 6 GB page file on a traditional mechanical 5400rpm SATA drive.  Does Windows take into account the difference in the performance characteristics between the two drives when deciding which page file to use?  If it matters, I'm asking about Windows 7 and higher.  I reviewed this  but it doesn't appear to factor in the case of dissimilar storage speeds. Block cipher fixed points (plaintext equal to ciphertext) How do you delete untracked local files from your current working tree? Advanced search in Google Contacts Is there any way to do perform advanced searches in Google Contacts?  For example, wild card operators, AND operator, OR operator etc?  I want to search anywhere in a name, not just the beginning of a name. (i.e if I write 'ac' it should display Jack as well)