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904 posts tagged with math.

Displaying 101 through 150 of 904. Subscribe:

## How do you compare profits to loss due to inflation?

I'm trying to compare the compounded losses due to inflation to non-compounded profits. E.g. if inflation makes me lose 3% of an investment each year, what % would I need to profit each year in order to exactly keep up? This is tricky because the profit is not compounded the way inflation is. I'm not looking for an answer to this specific question, but rather, looking for a tool or method to do this kind of math. [more inside]

## Statistics Book for an interested teen

My teen aged niece has suddenly found a strong interest in statistics. What book would you recommend for a 14 year old who has good, but not advanced, math skills?

## Help! Can I normalize statistical coefficients?

With deadline looming, stats consultant has bailed. Simple queries need resolution. Help?
I am working on a data graphic that involves statistical calculations about survival rates for startup businesses, correlated with certain tangible and intangible factors. The raw data (about survival/closure/merger outcomes) has already been investigated, and the original researchers (who are awesome) have generated some interesting correlations using univariate regressions and Cox regressions. For my output I am relying on their statistically significant findings, wanting to create comparisons among the univariate coefficients. Not sure my methods are kosher and would appreciate consultation. Avalanche inside. [more inside]

## Math-related field trip destinations for Bay Area HS students?

I teach math to high schoolers in the San Francisco Bay Area. I'd like to get them out of the classroom on a field trip to a local math-themed destination. Any suggestions? [more inside]

## Methods of approximation?

I've never been very good at either math or at eyeballing things like weight or dimension, but was thinking recently about how to more or less accurately weigh things without using a scale. What good methods are out there to approximate other kinds of measurements? [more inside]

## Which algorithms changed the world?

A recent post to the blue proposed a set of equations that changed the word. As a computer professional, I'm curious, which algorithms transformed the world? [more inside]

## Math Camp for Economist help!

I'm basically teaching myself how to do pass an PhD economics placement test, and I'm looking for resources to learn these things that aren't books. [more inside]

## What are inter-disciplinary and atypical uses for math MSc?

I have just completed my MSc in mathematics in Europe. I do enjoy math, but I spent my uni years feeling like a autodidact hippie marooned on an island full of Mr and Mrs I-Want-A-Good-Job. My main interests revolve around humanities (literature/history/anthropology) and economics (but not finance), and instead of starting a "stable" well-paying career I dream about something inter-disciplinary. I am very open to earning little money and relocating just to do kind of work that engages those skills. What are some random uses of my degree? [more inside]

## 4x+y+2z=100, x>y, y>z, x+y+z=j, 3x+z=k, j>k, j+k=100.

4x+y+2z=100, x>y, y>z, x+y+z=j, 3x+z=k, j>k, j+k=100. WolframAlpha can only give me alternative forms or a solution involving 'real and imaginary parts of z'. Is there a solution I can count on my fingers? [more inside]

## Math Careers

Non-obvious careers for someone with a B.S. in Applied Mathematics? [more inside]

## Math? College?

The best way to pursue my college goals given my situation. [more inside]

## Calculus Rabbit?

Is there a game like Math Rabbit out there, but for calculus? Specifically looking for something with lots of game-interface, not Khan Academy.

## what percent will result from combining two types of milk?

If I add 1/100 to 2/100, I get 3/100 or 3%. But if I add one hundred apples, one of which is red, to one hundred apples, two of which are red, I will have 3/200 or 1.5%. I'm very confused now as to what percent milk fat my milk will be if I combine the two types of milk (1% and 2%) together.

## Converting math to code

Wanting to code. Can't read calculus. Kinda stuck. Help? [more inside]

## Math Filter: What is Calculus?

My son would like to know: Is there more to calculus than functions, examples of functions, various formats for presenting functions, and so on? That is, does calculus have unique to it other tools that are not just variations on functions? [more inside]

## Math book recommendations?

Years ago I read John Derbyshire's

*Prime Obsession: Bernhard Riemann and the Greatest Unsolved Problem in Mathematics*and loved it. Now I'm studying formal theory/real analysis and I'm finding it really it interesting, but would like to be able to spend my downtime reading about the background of math and also explains some of the concepts. Thanks!## Maximum sum of numbers, one from each set, with constraints

Working on a personal project, I am running into a number of math problems of the kind described within. I am not a math expert, so I don't know what to call these kinds of problems, so I don't know how to search for information about them. [more inside]

## Help Me Learn Math!

I will be returning to school in the fall to start prerequisite courses for a Physical Therapy program.
I don't know math.
The last time i took math was in high school, and it was basic geometry.
I would like to teach myself primarily, so that i can test into higher classes. The goal is to be able to test into pre-calc, so that i can also qualify for the physics classes as well.
Any suggestions? I don't really care about the method. I was thinking about buying a textbook, but i was unsure of which ones to get.
Thanks.

## Help Building a Gameplan For a Career In Market Research Analysis

So, I’ve been doing a lot of thinking about how to land a career in market research analysis. Below are the steps I’ve laid out for myself. Could you tell me if this is a good game plan to get where I want to go? [more inside]

## Can you answer this question before my traffic court at 9 am?

I'm due in traffic court at 9 am. Help me use math to prove I didn't do it. [more inside]

## 2 problems of combinations and permutations.

How many unique ways are there to put X rocks into Y boxes?
(Given two different sets of attributes for both the rocks and the boxes.) [more inside]

## Mortgage shenanigans?

We have an excessive interest rate on our home. We tried to refi, and the appraisal came in a good $40,000 less than it needed to in order to qualify. So some of our more numerically-talented friends ran some numbers for us in an attempt to find alternative solutions and found a weird discrepancy that makes it appear we owe $15,000 more on the loan than we do... [more inside]

## Pythagorean Theorem in the original Greek

I'm looking for a textual version of

*a*^{2}+*b*^{2}=*c*^{2}that is as old as possible, among all the Greek sources. [more inside]## How do I calculate combined percentages?

Mathfail: I'm considering supplementing my cat's food with plain meat. I'd like a rough idea of how much it would bump percentage of calories from protein and fat. [more inside]

## Should my math student have some Unix skills?

I think my son, who is on an AP math trajectory in high school, would benefit from getting some familiarity and basic programming skills in the Unix world. I've noticed math depts in some universities include study of these skills in early years. Are there some tutorials we could use in the OS X environment to get a leg up? [more inside]

## What Major and Career Should I Look At If I Enjoy Math?

In studying for my Behavioral Statistics final (it’s a statistics class dealing with psychology research methods) I’ve realized something. I actually kind of enjoy math. As long as I don’t have to memorize formulas (as long as they are right there as I’m going through the work) it’s actually kind of comforting and fun. In fact, every math class I’ve taken in college (I’ve taken two remedial algebras, college algebra, and regular statistics before this class) I’ve enjoyed and made an A in.
I’m really struggling about what I want to major in (I’m in psychology but I don’t have it in the gas tank to get a PhD), but I know that a lot of people don’t like math. They don’t get it. I do, so I’ve got something there, right?
The only problem is, I don’t know what to do with it. These are the parameters… maybe you can think of something that fits? [more inside]

## Size of earth to solar system vs drop of water to Mt Everest?

Can someone please tell me (if you could show calculations, that would be wonderful) what the ratio of ratios would be for these two numbers: a) the volume of the earth compared to that of the solar system and b) the volume of a drop of water compared to that of Mount Everest?

## Why is the center of a circle often given as (h, k)?

Why are the letters 'h' and 'k' often used to represent the center of a circle in the standard equation of a circle:
(x - h)

^{2}+ (y - k)^{2}= r^{2}are 'h' and 'k' short for something? I might guess 'h' is short for 'horizontal', but I can't imagine what 'k' is for. [more inside]## What's a good topic for a one-hour math lecture?

I work as a math tutor at a community college and have the opportunity to spend an hour teaching math to a group of students preparing for a the college's math placement test. Now, I don't know what's on the placement test, but I want to teach something that's more engaging and conceptually accessible than "here's how to multiply (4x+3)(2x+5)", since I can't possibly review all of high-school math in an hour and don't think the students will get much from just another lecture. What are some interesting topics that I can explore that will be accessible and memorable?

## Article about Common Core math

Trying to find an article I read sometime in the last three months about Common Core math. [more inside]

## [MathFilter] Taking for-credit math classes online

For professional and academic reasons, I need to take a number of college-level math classes (mainly Calculus and Linear Algebra) in a relatively short period of time (4-6 months). They need to be online, for-credit, and I need to be able to do them at my own pace, meaning faster than a normal 1-course-per-semester flow. I've already found https://netmath.illinois.edu/, but the classes are terribly expensive, so I'd like to learn of other alternatives that don't cost as much.

## Von Neumann I am not

I’ve spent my 20s building a BS “identity” as an “analytical type of person". Help me grow up. Snowflakes inside. [more inside]

## Calculus after being away from algebra for some time. Help me.

I am going to grad school in the fall. Hooray! Problem: I have to take calculus before I start and I am kind of freaking out. [more inside]

## Chance of event with small sample size, based on larger related sample?

Can/how can one improve the estimate for a chance of an event with a small historical sample size by utilizing the chance of a related event with a large historical sample size? Example and half-assed guess inside. [more inside]

## You Can't Handle the (Next) Proof!

Working through Apostol's Calculus Volume I for personal development. Stuck on a proof, again. Can you help? [more inside]

## How to take scientific notes efficiently?

What is the best way to take grad level notes that feature tons of text, math equations and diagrams, during class, while reading books, and while reading research?
Ability to search and organize a huge plus!
Digital or non-digital solutions considered. [more inside]

## In Need an Nerdy T-Shirt for Tomorrow (3.141592654...)

Okay, I'm in NYC and I need a PI related T-Shirt for Pi-Daytomorrow... Anyone know of any stores where I can get one? (It's too late for an online order)

## Why do we have order of operations in arithmetic?

Why do we have order of operations rules in arithmetic instead of just strictly evaluating expressions from left to right (possibly with parenthesis for grouping if we really wanted to change the order)?

## Is this science or a sort of engineering? How do I learn more about it?

My ignorance of science and engineering concepts, procedures, and methods of calculation is holding me back from tackling a whole mess of fun stuff. But what fields am I even interested in, and how can I learn more? Where do I begin? [more inside]

## Well-written math

Which mathematicians write exceptionally well or exceptionally clearly? (Individual books or articles would also be acceptable.) [more inside]

## Where can I take an online linear algebra course this summer?

I have $800 for tuition reimbursement, and would like to take a linear algebra online course this summer. It doesn't matter if its for credit or not. Thanks!

## Regarding the M in STEM

What are some of the newest methods being used these days to teach young children arithmetic? [more inside]

## Was Fifth Grade math always this hard?

Can you show us how to solve a math word problem? [more inside]

## Singapore Math

I'm trying to help my 3rd grader with his math homework, but we are stuck on one problem. I can solve it using Algebra, but I'm trying to figure out how to explain it to him using the Singapore method that he's taught in school. Note that he hasn't learned how to add negative numbers, which puts a crimp on the methodology. [more inside]

## You Can't Handle the Proof!

Working through Apostol's Calculus Volume I for personal development. Stuck on a proof. Can you help? [more inside]

## Table top brainteaser puzzles

## Why can't I differentiate this nomal/Guassian distrubution?

Have a look here. I'm assured that differentiating 1, with respect to

*x*, gets you 2. Now 2 is - I think, and correct me if I'm wrong - equivalent to 3. The problem is I can't see how 3 is the result of differentiating 1. What's more, an online solver produces something (that looks) very different. Can someone help me out?## What to include in a training on maths for business people?

I've been asked at work to come up with a list of topics that could be included in a training course around basic maths for business people, and I am finding it hard to find suggestions for topics. [more inside]

## The Gambler's Fallacy, of course. But maybe...

A coin flips three times and comes up heads 2/3. Not suspect.
But a coin flips 100,000 times and comes up heads 2 out of 3 times, that starts to look fishy. The standard probability of this is always roughly 50-50, but assuming a 2/3 ratio pointing to a "rigged" coin, how could you plot the increasing likelihood that a given coin is rigged? [more inside]

## Percentage Question

Help me understand percentages. [more inside]