Ask MetaFilter questions tagged with math
http://ask.metafilter.com/tags/math
Questions tagged with 'math' at Ask MetaFilter.Tue, 17 Jan 2017 10:20:10 -0800Tue, 17 Jan 2017 10:20:10 -0800en-ushttp://blogs.law.harvard.edu/tech/rss60Data Munge: Uknown combination of 7 numbers produces a given number.
http://ask.metafilter.com/304942/Data%2DMunge%2DUknown%2Dcombination%2Dof%2D7%2Dnumbers%2Dproduces%2Da%2Dgiven%2Dnumber
<strong><em>Data Munging Pros</em></strong>: In a spreadsheet with ten data columns, Column "A" is related to columns "B" through "J" in that some unknown combination or interaction of some or all of them will produce the data in Column "A". How do we determine what that combination is? (I can't even find what this type of problem is <em>called</em>, and I've not been able to find any productive Google search terms.) A more thorough explanation/example is provided in-thread. Quick example, very slightly different than the one above the fold:<br>
<br>
Say I have two spreadsheets that I know are related in some way.<br>
<br>
Spreadsheet One has two Columns: "Alpha" and "Bravo". An example row for Alpha and Bravo are:<br>
<br>
<blockquote><code>Alpha = 42,492<br>
Bravo = 3,115</code></blockquote><br>
<br>
Spreadsheet Two has seven fields: "Charlie" through "India". Example rows for Charlie through India are:<br>
<br>
<blockquote><code>Charlie = 39,912<br>
Delta = 4<br>
Echo = 17,664<br>
Foxtrot = 11,313<br>
Golf = 7,719,011<br>
Hotel = 15,084<br>
India = 412</code></blockquote><br>
<br>
Now in this example, example Alpha (42,492) is the relationship:<br>
<br>
<blockquote><code>[Charlie + Echo - Hotel]</code></blockquote><br>
<br>
And example Bravo (3,115) is the relationship:<br>
<br>
<blockquote><code>[(Hotel / Delta) + Foxtrot]</code></blockquote><br>
<br>
Easy enough to do with Two Columns in Spreadsheet One and only seven columns in Spreadsheet Two. But for my problem, I have 5 entries in "One" and I have something like 35 entries in "Two".<br>
<br>
What is this type of problem called? What is the way to go about attacking it? Assume that the only operators involved in the relationship will be "add/subtract and multiply/divide".<br>
<br>
Thanks so much for your time and your expertise.tag:ask.metafilter.com,2017:site.304942Tue, 17 Jan 2017 10:20:10 -0800jjjjjjjijjjjjjjMath For Spacing Out Three-Day Weekends, But Accounting for Holidays
http://ask.metafilter.com/304816/Math%2DFor%2DSpacing%2DOut%2DThree%2DDay%2DWeekends%2DBut%2DAccounting%2Dfor%2DHolidays
I'm a big honkin' geek, and I would like to figure out an Excel formula I could reuse from year to year to space out my vacation day choices -- but including holidays, which would prevent even distribution. How can I still get as close as possible? More inside. So, I'd like to be able to space out three- or four-day weekends across a year an Excel formula, but I can't seem to wrap my head around how to structure the formula.<br>
<br>
The issue is that it is <i>not</i> just dividing the number of weeks in a row by my number of vacation days (or half my vacation days, if I do 4-day weekends) ... because as an office we have certain weekends off as holidays ... Memorial Day, July 4th, Labor Day, etc. I'd like to include those when considering the "spacing", but doing so will throw off the even distribution of the dates -- so I'm not sure how to set up the math on this.<br>
<br>
Thoughts?tag:ask.metafilter.com,2017:site.304816Fri, 13 Jan 2017 15:28:33 -0800WCityMikeI am the auntie in charge of turning the kid into a nerd.
http://ask.metafilter.com/304578/I%2Dam%2Dthe%2Dauntie%2Din%2Dcharge%2Dof%2Dturning%2Dthe%2Dkid%2Dinto%2Da%2Dnerd
A low-income, uneducated friend of mine is utterly, utterly terrified that her 14-month-old baby will continue the cycle of poverty and become a statistic. Specifically, she wants help ensuring that he learns to read, write, and do math on schedule. Difficulty level: the only time she has to do pre-reading and pre-math activities with him is during their twice-daily 3 hour train commute while she's exhausted. Many snowflakes here, some details of which I'm reluctant to post online for fear of being too personal, but suffice it to say that her fears are not unfounded at all. The only childcare currently available to her is completely inadequate and neglectful, and won't be reading to him or doing counting games. (She would need to change jobs in order to get him into a real daycare, which she is working on, but it's not so easy when you don't have a GED.) She doesn't trust the schools to handle this, as they've utterly failed her other children. And she's limited in what she can do, not being able to lug books or toys around with everything else she has to bring. <br>
<br>
Considering the Finnish Math thread, I was sure I'd be able to find a book with activities that didn't require a stable place, writing, worksheets, etc. (That bit about "find a stick as long as your foot" is certainly something she'd be able to do with him, once he's a little older.) But I'm not sure a book would even be used, so maybe a smartphone app to prompt her and give her ideas?<br>
<br>
(Why can't we have the "Young Ladies Illustrated Primer" of sci-fi fame already?)tag:ask.metafilter.com,2017:site.304578Sat, 07 Jan 2017 13:38:39 -0800SoliloquyMath review for wannabe computer science student
http://ask.metafilter.com/304026/Math%2Dreview%2Dfor%2Dwannabe%2Dcomputer%2Dscience%2Dstudent
Next semester, I will be taking a university class on the mathematical methods used in studying computer science. My last math class was a very, very long time ago. What topics should I review in the next month so that I won't be totally lost in my class? I'm a grownup who works at a university. This semester, I took the Intro to Computer Science class for CS majors. I enjoyed it and did well. Next semester, I'm signed up to take the second class in the CS major, which is a math class. According to the course description, the topics include:<br>
<br>
<blockquote>mathematical logic; proof techniques, especially mathematical induction; set theory, functions, and relations; procedures, recursion, and operation counts; recurrence relations; analysis of algorithms; counting methods, permutations and combinations; graphs and trees.</blockquote><br>
<br>
There's no pre-requisite, although calculus is recommended. The prof has indicated that they're using calc as a proxy for being able to think mathematically, and it's not necessary to know calculus to do the work. I think I can do it: I really loved doing proofs in high-school geometry, and I've done well in CS classes that have a reputation for being tough. Even so, I'd like to review some math in the month before the class starts. It's been 20-odd years since my last math class, which was pre-calculus, and I don't remember anything. If I were going to watch some Khan Academy videos and such to prepare for this class, what topics should I focus on? Are there any particularly great resources to use?tag:ask.metafilter.com,2016:site.304026Thu, 22 Dec 2016 05:41:51 -0800ArbitraryAndCapriciousTips for neatening, formatting, and organizing self-study math homework?
http://ask.metafilter.com/303464/Tips%2Dfor%2Dneatening%2Dformatting%2Dand%2Dorganizing%2Dself%2Dstudy%2Dmath%2Dhomework
Please give me your tips on making handwritten math homework more attractive and useful, so I can enjoy reviewing my self-study math notebook. I want to have nicer looking math notes. I'm reviewing high school math (algebra, geometry, trig) and studying college math I never had (calculus, linear algebra, whatever).<br>
<br>
I have lots of great textbooks with problems and solutions.<br>
<br>
When I'm working the practice problems, though, I just grab scratch paper and write things out haphazardly, often in as little space as I can (so I'll end up with three or four sloppy columns on the page).<br>
<br>
I'd like to aim for something more attractive and legible, in the hope that I might enjoy looking back over them in the future.<br>
<br>
So please give me all your best tips and ideas for creating my personal math notebook, writing out math homework attractively, and integrating it with notes (chapter summaries and so on). Links to examples would be great.<br>
<br>
Please feel free to be very basic and explicit, like "write fractions so they take up two lines" or "circle the final answer" or "use lined paper" or "use graph paper" or whatever.<br>
<br>
Suggestions on things to include besides worked problems (formats for chapter summaries, etc.) would also be great.<br>
<br>
Thank you!tag:ask.metafilter.com,2016:site.303464Tue, 06 Dec 2016 09:39:35 -0800kristiCan p → q |- ¬p ∨ q in intuitionistic logic?
http://ask.metafilter.com/303275/Can%2Dp%2Dq%2Dp%2Dq%2Din%2Dintuitionistic%2Dlogic
Can you prove p → q |- ¬p ∨ q without using the law of the excluded middle or its equivalent? I'm going through a logic book (introductory) and I have an intuition that proving this isn't possible constructively, but I'd like a confirmation.tag:ask.metafilter.com,2016:site.303275Thu, 01 Dec 2016 15:42:35 -0800Monday, stony MondayResources for Arabic speaker (ESL) learning lab maths?
http://ask.metafilter.com/302760/Resources%2Dfor%2DArabic%2Dspeaker%2DESL%2Dlearning%2Dlab%2Dmaths
An Arabic-speaking student with weak English needs a crash course or quick reference for the basic maths required to do postgraduate biology bench research. Any suggestions for resources I can point them to? It needs to be in basic English, avoiding unnecessary idiomatic and technical language as much as possible or -- ideally -- in Arabic with reference to English terms so they can learn more easily then have useful conversations about it in our English-speaking lab.<br>
<br>
Their current level of maths knowledge is less than I'd expect from a bright high school science student. Specific topics that need to be covered include but are definitely not limited to:<br>
Molar concentrations: the basic concept (what a mole is and Avogadro's constant, the difference between e.g. 0.5M and 50%w/v), and how to do calculations to make molar solutions<br>
SI units, with prefixes and what they mean (milli- micro- nano-, etc)<br>
Rudimentary statistics: Normal distributions, standard deviations, null hypotheses, t-tests, p values, power calculations<br>
Ideally, making and understanding simple formulae in Excel.<br>
...most other maths that you might imagine a biology PhD candidate would need.<br>
<br>
If <a href="http://www.amazon.com/exec/obidos/ASIN/1936113716/metafilter-20/ref=nosim/">Lab Math</a> has an arabic equivalent, it might be an ideal start. I'm doing my best to teach them piecemeal as things come up, but really they need something they can sit with to work from the basics up, and then refer to occasionally.<br>
<br>
NB: This is in the UK, where PhD candidates don't attend taught courses in the same way as candidates in the USA. I'm looking for suitable courses in the uni that they could join, but that's outside the scope of this question.<br>
<br>
Thanks!tag:ask.metafilter.com,2016:site.302760Fri, 18 Nov 2016 05:39:54 -0800metaBugsVehicle Attrition Rate from 1965?
http://ask.metafilter.com/302576/Vehicle%2DAttrition%2DRate%2Dfrom%2D1965
Math Geniuses, I am trying to figure out how many trucks from 1965 may still be in operation. I'm using 2.5% totaled or lost per year, over 51 years. If there were 3250 produced in 1965, how many would be left today? My <a href="http://scoutparts.com/gallery/photos/International_Harvester_1964_Scout/1964%20International%20%20Scout%20red%20carpet.jpg">Scout 80 Red Carpet Special</a> was produced in 1964-5 to celebrate the first 100,000 Scout 80s made. 3250 were produced. I just want to estimate how many are left. I'm assuming a 2.5% kill rate a year. Is there a simple equation I can use on my calculator so I can vary the attrition percentage?tag:ask.metafilter.com,2016:site.302576Sun, 13 Nov 2016 18:28:52 -0800atomicmediaArt recommendations for a gift to a math student?
http://ask.metafilter.com/302549/Art%2Drecommendations%2Dfor%2Da%2Dgift%2Dto%2Da%2Dmath%2Dstudent
My boyfriend's birthday is approaching and I want to get him a piece/a series of art to hang in his almost entirely blank room - he does appreciate art, just doesn't go out of his way to collect adornments of any kind. He's deeply interested in computer science and pure math and I have very little background in either. I'd like to select a work that resonates with him, that he can admire compositionally and that in some way reflects the concepts that he studies. < We go to museums together occasionally, which he always enjoys, but he doesn't have a favorite artist or period. In general, he likes very simple, well crafted things. And the color green. <br>
<br>
I think something abstract would be ideal. I suppose I'm imagining an illustration of a concept, but, as this is not my background, I don't know what illustrations of what concepts are particularly visually pleasing and also particularly relevant. <br>
<br>
Pointers in any direction would be greatly appreciated.tag:ask.metafilter.com,2016:site.302549Sun, 13 Nov 2016 01:06:01 -0800reedfieldsZero-Knowledge Negotiation Protocol
http://ask.metafilter.com/302494/Zero%2DKnowledge%2DNegotiation%2DProtocol
Can we do a deal? Suppose you have two people negotiating to buy / sell something. Seller has a maximum they're willing to pay, and Buyer has a minimum they're willing to accept. They can keep going back and forth with bids to try to agree, but is there a protocol by which they can get a yes/no answer to the question, "is the other side's limit higher/lower than my limit?" It doesn't have to (shouldn't!) say what the limits are, just that there exists an overlap between the highest bid and the lowest ask.<br>
<br>
Obviously, if you know that there is an overlap, and the <i>size</i> of the overlap, you can calculate the other side's number. So the protocol needs to hide the size of the overlap from both parties, and just produce "Overlap Yes" or "Overlap No."<br>
<br>
One simple solution would be to use a trusted third party, but is there a protocol that the buyer and seller can do on their own?tag:ask.metafilter.com,2016:site.302494Fri, 11 Nov 2016 11:58:54 -0800spacewrenchMath for Board Game Design?
http://ask.metafilter.com/301758/Math%2Dfor%2DBoard%2DGame%2DDesign
I'm making board games as a hobby and I'd like to have a better understanding of statistics and similar math topics in order to start the design stronger outta the gate - having better balance instead of just guessing. What sorts of resources are out there and what are the best branches of math to look into? I'm really not great at math so introductory type things are desired, maybe a site with simple formulas from stats? What other math is important in design besides statistics/probabilities, etc. Explanations of differences between dice vs cards probabilities, all that sort of thing. <br>
<br>
Appreciate any sites/books/videos you may have links for (or comments with some basics, even :)) Thanks!tag:ask.metafilter.com,2016:site.301758Fri, 21 Oct 2016 11:01:45 -0800symbioidFinding near-misses between lines in 3D
http://ask.metafilter.com/301519/Finding%2Dnear%2Dmisses%2Dbetween%2Dlines%2Din%2D3D
Is there a good (read: well-known/efficient) way to find the "near-miss" intersection of 3 lines in 3D space? The lines almost, but don't quite, cross each other (<a href="http://i.imgur.com/8L5swDR.png">image in an attempt to illustrate the problem</a>) (I'm doing this in MATLAB at the moment, but would appreciate general/conceptual ideas as well.)<br>
<br>
What I've been doing so far is to map each of the three vectors onto a regular 3D point cloud using linear interpolation (matlab's "scattered interpolant") and then summing the three point grids to find points crossed by all three lines. This seems to work as long as I define a sufficiently dense point grid, but it also feels to me like an extremely inefficient way of doing things - for an NxNxN point cloud I end up having to sit through matlab chugging along interpolating N^3 points, most of which are zeros.<br>
<br>
The problem of finding near-misses between lines seems like it would be the kind of thing that someone a lot smarter than me would have thought about before. Is there some sort of generally accepted solution for this kind of thing, or is it one of those conceptually simple problems that end up being a lot more complicated than it seems? Assume I have very little knowledge of, say computer graphics or any other area where this problem might be applicable - I'm just stumbling around and trying not to reinvent the wheel, here. Thanks!tag:ask.metafilter.com,2016:site.301519Fri, 14 Oct 2016 11:04:27 -0800btfreekIn lieu of quals...
http://ask.metafilter.com/301301/In%2Dlieu%2Dof%2Dquals
I'm currently in the first year of a PhD program in physics. Right now I am just taking classes. My school does not have a qualifying exam, and there's not much I need to do outside of my classwork. However, I don't want to live from homework to homework -- so I'd like to set aside some extra time for textbook-reading and problem-solving. Have you done this? Tell me about your experience. I've done this in the past; I'm capable of sitting down for several hours on an evening or weekend and walking through a piece of textbook. I'm just looking for any specific, extra things you noticed that might be helpful.<br>
<br>
To my situation: I'm still deciding what research (cond-mat theory?) I'd like to get into, and have been doing the usual -- attending seminars, getting to know professors, etc. But there's plenty of "textbook stuff" that I need to learn over the next year or three, so I'm just going to have to crunch through this part.<br>
<br>
To the question: where did you work? When did you study during the week? Were there specific ways in which you thought about the texts/problems differently from your typical course material? What did you do when you got stuck? How fast did you move along? What was most useful for remembering the appropriate connections, scales, and approximations? Did you work with other students, or did you mostly work alone? About what did you have to be brutally honest with yourself? Any other advice for grad school self-study?<br>
<br>
Thanks!tag:ask.metafilter.com,2016:site.301301Fri, 07 Oct 2016 13:23:21 -0800miniraptormath/geometry/construction query!
http://ask.metafilter.com/301277/math%2Dgeometry%2Dconstruction%2Dquery
Suppose you have to install new moulding in a house. Suppose also that it's a huge house with many rooms large and small, and many windows of different size. This means that you end up needing many different lengths of wood... So you've done all the measuring and you have a long list, and it's time to order the wood. The wood is available in one length, say ten feet. So here's my question:<br>
<br>
How do you most efficiently divide your different lengths between the ten-foot sections with the least leftovers? (And in the process find out the minimum you need to buy) <br>
<br>
I know you could do it all "manually", starting with the longest cuts and seeing what fits the leftovers, but...<br>
<br>
Isn't there some online tool for this? Or some Excel thing? It seems like such a fundamental thing, the efficient use of material, that somebody somewhere has worked out something for it. But I've gotten nowhere with Google. I don't even know what to ask it (you may not know the answer, but if you can even supply the name for the problem, that'd at least give me a lead).tag:ask.metafilter.com,2016:site.301277Thu, 06 Oct 2016 19:59:04 -0800Rich SmorgasbordToo Many Strata To Sample
http://ask.metafilter.com/300748/Too%2DMany%2DStrata%2DTo%2DSample
I have multiple independent variables that I want to stratify my sampling across, but the result would be way more strata than I can sample. Is there a way to stratify across different character states for each independent variable without creating strata for the interactions of each? Example inside. In my example I have independent variables Color (red, orange, yellow, green, blue, purple), Shape (square, round, sinusoidal), Size (small medium large), and Flavor (apple, banana, grape). If I tried to stratify my sampling across each of these I would get 162 strata. My population is only about 1,000 individuals though! I can’t pull 30 samples each from 162 strata. In fact, there may not even <em>be</em> any large square blue grapes (for example).<br>
<br>
I don’t really care about the effect of the possible interaction between the terms though. Can I design a sampling regime that would make sure I get a randomly selected 30 of each color, 30 of each shape, 30 of each size, and 30 of each flavor, but not try to get 30 of each combination of color, shape, size, and flavor?<br>
<br>
Why is this a bad idea? Or if it’s not, is there an established way of designing such a sampling regime?tag:ask.metafilter.com,2016:site.300748Wed, 21 Sep 2016 08:49:13 -0800agentofselectionResources for helping young student with idiosyncratic math issue?
http://ask.metafilter.com/300371/Resources%2Dfor%2Dhelping%2Dyoung%2Dstudent%2Dwith%2Didiosyncratic%2Dmath%2Dissue
I"m tutoring a 12 year old girl in math and she displays an idiosyncratic learning disability / learning style. (Specific issue was in learning to calculate the area of a rectangle, an example was used of a rectangle with area of 48 and she didn't understand why all rectangles don't have areas of 48.)
Could someone offer suggestions for this specific student, or, more generally, a resource where I might be likely to find others who might have run across similar students?tag:ask.metafilter.com,2016:site.300371Mon, 12 Sep 2016 04:28:16 -0800Jon44Can you figure out the probability of a specific outcome?
http://ask.metafilter.com/300348/Can%2Dyou%2Dfigure%2Dout%2Dthe%2Dprobability%2Dof%2Da%2Dspecific%2Doutcome
I work in a field where we think about possibly dangerous people. If Mr. X is a poor driver and has a 5% chance of running a red light in the next month, can you know the probability of him running a red light at a specific intersection? Can you know a range of probabilities for that specific intersection? What if it's the intersection that he drives through most often? I think this likely has an easy answer but none of us can clearly explain it so we keep talking about it.tag:ask.metafilter.com,2016:site.300348Sun, 11 Sep 2016 11:30:32 -0800kerfMath Facts
http://ask.metafilter.com/299965/Math%2DFacts
Beyond multiplication tables, what sort of mathematical knowledge is useful to have memorized?
Also, what alternative methods have been of help for you? I've been working my way through Khan Academy sans calculator, so tips and tricks for solving without getting into ridiculous numbers would be helpful. For instance, factoring numbers when solving division problems and canceling out. <br>
<br>
I know that understanding is more important than just rote memorization, but surely there are some things worth knowing. Not pi, I assume, but maybe conversions, squares, primes? <br>
<br>
'Foreign' practices are of considerable interest to me as well, learning lattice multiplication and Austrian subtraction has done me a lot of good. I tend towards the messier side, so anything that makes it harder to make foolish errors is appreciated.tag:ask.metafilter.com,2016:site.299965Thu, 01 Sep 2016 11:22:01 -0800TriflingThe Boozy Educational Series
http://ask.metafilter.com/299704/The%2DBoozy%2DEducational%2DSeries
I want to learn, from the beginning, with no pressure and a drink in hand. Help me come up with a boozy math/science online course curriculum. I didn't do particularly well in math and science throughout grade school, high school, and college. I got through the courses somehow but never had a passion for them, and I was always convinced they were beyond my capacity. It was a combination of passion-ruining parental pressure and teachers who never gave me a reason to care, I guess. It was only after schooling that I realized this stuff was super interesting and worth knowing. <br>
<br>
So, I want to give myself another shot at this education, from basically the beginning, going on (hopefully) through relatively advanced college material. I want it to be super low-key and low pressure, even if the material gets difficult - I should be able to have a drink or two and just follow along for the sake of learning, as if I were watching Netflix or something. Maybe I won't pick up on everything, but I should be able to work through a problem per session and basically understand how it works. It's okay if I have to occasionally rewatch material I didn't get the first time.<br>
<br>
Can you help me brainstorm a list of online courses that would be well-suited to this sort of "booze and learning" series? I want to start with really basic fundamentals, so for math, maybe we begin with arithmetic, then algebra, and then keep going, up to, say, differential equations and proof-based courses. Any free service will do - Coursera, Khan Academy, Youtube, not sure what's out there. If possible, the instructor should emphasize fascinating problems and keep giving me reasons to stay engaged. I know that can be a high bar when some of the material is going to be dry, though, so consider it optional.tag:ask.metafilter.com,2016:site.299704Thu, 25 Aug 2016 15:47:44 -0800najuHow much math should most college students be able to learn?
http://ask.metafilter.com/299681/How%2Dmuch%2Dmath%2Dshould%2Dmost%2Dcollege%2Dstudents%2Dbe%2Dable%2Dto%2Dlearn
I have read quite a few articles that state that there's no such thing as being bad at math, that often it is just the case that you haven't had a specific subject explained to you in a way that made sense to you, or that you just have to work harder at it. That resonates with me, but clearly there's a limit to that and I wonder what that limit is. I know that theoretical math at the university level is one of the hardest subjects and that even people who are the best in their class in high school often have trouble with that. So, I wonder if there is any consensus about what a level of math is that most college students could reach, given enough motivation and good explanations. I'm interested in both experiences from math teachers/people who took higher level math classes in college, and articles that are written about this.<br>
<br>
I'm in Europe so general explanations would be preferred because I have no clue what Americans learn in which classes. I'm assuming college students, so people who have the IQ/skills to go to college, but not necessarily people who had advanced math classes in high school.tag:ask.metafilter.com,2016:site.299681Thu, 25 Aug 2016 02:02:12 -0800blubI was told there would be no math.
http://ask.metafilter.com/299519/I%2Dwas%2Dtold%2Dthere%2Dwould%2Dbe%2Dno%2Dmath
I've crossed a bunch of plants with one another, and now have a bunch of berries on those plants. Each berry can contain way more seeds than I have room to pot up and grow out individually, so I'm trying to find the point of diminishing returns, where potting up additional seedlings stops giving me new and interesting results, but my math background is inadequate. A previous cross has given me thirteen distinguishable colorations. I imagine this isn't typical, but it's all the information I have so let's roll with that. <br>
<br>
In the previous cross, out of 75 seedlings, result A has occurred 22 times, B 15 times, C 7 times, D 5 times, E 5 times, F 4 times, G 3 times, H 3 times, I 3 times, J 3 times, K 2 times, L 2 times, and M 1 time. <br>
<br>
Assuming these results to be typical, how would I:<br>
• calculate the number of unique outcomes likely to result from potting up <i>n</i> seedlings<br>
• calculate the number of seedlings to pot up in order to have an x% chance of result Y?tag:ask.metafilter.com,2016:site.299519Sun, 21 Aug 2016 10:22:30 -0800Spathe Cadetinexpensive pathways for math greats?
http://ask.metafilter.com/299208/inexpensive%2Dpathways%2Dfor%2Dmath%2Dgreats
My older one is great at math, worried about UK student debt, and wants to have the university experience. Are there distance or residential sub-£18,000 math degrees anywhere that offer a level of student experience akin to the tutorial opportunity and entertainment a student in university might have, or companies or organisations geared to these experiences?tag:ask.metafilter.com,2016:site.299208Sat, 13 Aug 2016 07:10:51 -0800parmanparmanDo you have a vigor? A vigor for rigor?
http://ask.metafilter.com/299046/Do%2Dyou%2Dhave%2Da%2Dvigor%2DA%2Dvigor%2Dfor%2Drigor
A colleague mentioned a college course he took on rigorously proving commonly handwaved aspects of math. Help me find books or a syllabus relating to this! Much like <a href="https://www.youtube.com/watch?v=ZDOI0cq6GZM">Lyle Lanley's salesmanship</a>, my mathematical education has a bunch of handwaving (e. g. how the fundamental theorem of calculus is usually presented). A colleague mentioned once that he took a very satisfying course (don't know if it was undergrad or not) that consisted entirely of taking foundational mathematical concepts that are presented with a bunch of flimflam and rigorously proving/defining them.<br>
<br>
I want to reconstruct as much of that course, or something like it, as possible.<br>
<br>
Do you know of any books dedicated to that or publicly available syllabi covering courses like that? Help me actually know things that I just pretend to know.<br>
<br>
(Presented in the science & nature category rather than the more accurate philosophy & religion in the hopes of casting a wide net.)tag:ask.metafilter.com,2016:site.299046Mon, 08 Aug 2016 11:34:22 -0800The GafferI have excel and a sense that this is possible
http://ask.metafilter.com/299021/I%2Dhave%2Dexcel%2Dand%2Da%2Dsense%2Dthat%2Dthis%2Dis%2Dpossible
So imagine I have a population of like 100,000 people. And I have goals for them to achieve for which they get money. Now I want to calculate what my budget might be. To keep it simple lets say I have 5 goals. I imagine 80% of the people will achieve 1 goal, and some lesser percentage will achieve 2, and a virtually none will achieve all 5. <br>
<br>
Each goal might be worth $50<br>
<br>
How can I set up an excel sheet to simulate this world where I can play with the variables? My biggest confusion is where 1 person achieves more than one goal.tag:ask.metafilter.com,2016:site.299021Sun, 07 Aug 2016 22:39:13 -0800jander03Help with Excel formula to compare 1 column of numbers to other columns.
http://ask.metafilter.com/298334/Help%2Dwith%2DExcel%2Dformula%2Dto%2Dcompare%2D1%2Dcolumn%2Dof%2Dnumbers%2Dto%2Dother%2Dcolumns
I have an excel sheet with 4 columns of numbers. The first column is a recent donation amount. The other three columns were the prompts of donation amounts, (the Reach, the Target, and the Anchor). Is there an excel formula that can compare these four columns? I would like to use a formula to compare the donation amount to the three other columns and output results that would say the donation was, Above Reach, Equals Reach, Between R and T, Equals Target, Between T and A, Equals Anchor, and Below Anchor. Is there an easy way to do this?tag:ask.metafilter.com,2016:site.298334Tue, 19 Jul 2016 07:37:54 -0800andoatnp