## Too Many Strata To Sample

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.
posted by agentofselection on Sep 21, 2016 - 6 answers

## Statistical framing of the engineering and extremism article

Reading this article on the blue got me thinking about conditional probabilities, prediction and causality. I came up with an analytical framing of what I think the article is saying and would be grateful if stats/social science Mefites could tell me if it seems accurate or else set me right.
posted by mister_kaupungister on Mar 25, 2016 - 3 answers

## Calculating the probability of a scenario that might happen by chance

I have to validate some input for a database, and I want to present the user with a mathematically accurate estimate of the percentage of data that they entered which may be invalid. The problem is that valid data looks like invalid data 10% of the time.
posted by zixyer on May 8, 2015 - 12 answers

## Probability distributions and their practical applications

I am looking for a resource that lists probability distributions and their common real-world applications. For example, I'd expect to see: Lognormal - daily returns in the stock market. Poisson - failure rates for mechanical equipment, ...
posted by wivy on Feb 19, 2015 - 6 answers

## Best or most appropriate Statistic method to Use.

I have a statistics and/or probability question and the last time I took a statistics class Vanilla Ice and Andrew "Dice Clay" were multi-millionaires. I am not looking for a problem to be solved, I am asking what statistical technique should I use to determine if a time series of data is due to randomness or not.
posted by otto42 on Jan 27, 2015 - 12 answers

## Statistics are hard.

How do you calculate the probability of something when it's not as simple as "do it a bunch of times"? Specifics inside.
posted by Dilligas on Jan 17, 2015 - 9 answers

What formula do I need to determine the probability that a set of size N contains two elements, each appearing with a specific frequency?
posted by Ender's Friend on Jan 4, 2015 - 16 answers

## Math Problem

posted by BeaverTerror on Dec 4, 2014 - 9 answers

## Has a major lottery ever produced a result that doesn't look random?

Every outcome in a fair lottery is equally probable, yet some results display obvious patterns and feel less likely to the statistically uninformed. Nobody would blink if a six-number lotto draw came up with (3,12,27,31,40,44), but a result of (1,2,3,4,5,6) would probably make the news. Has this ever happened in a major lottery? If yes, what was the public responce?
posted by Dr Dracator on Nov 6, 2014 - 10 answers

## 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.)
posted by CustooFintel on Jun 4, 2014 - 18 answers

## 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.
posted by Flunkie on Mar 20, 2014 - 16 answers

## I'm having trouble understanding likelihood ratios and diagnostic tests.

I'm struggling to understand likelihood ratios (LR) in the context of diagnostic tests, and why a positive LR is influenced by the sensitivity of the test.
posted by cacofonie on Aug 1, 2013 - 6 answers

## Is there a name for this logical fallacy? It has to do with statistics.

The fallacy is assuming that statistic information about a thing is more relevant in dealing with a particular instance of that thing than available first-hand data.
posted by CustooFintel on Mar 12, 2013 - 17 answers

## Human Random Generator

Can you think of a method that allows an individual to pseudo randomly create a sequence of numbers (at the very least the randomness is opaque to the minds of other people) assuming said individual may only use his mind and body (no physical tools are allowed)?
posted by Foci for Analysis on Dec 21, 2012 - 7 answers

## What does a professional statistician do?

(Good) jobs involving probability and statistics other than math teacher or actuary?
posted by CustooFintel on Dec 3, 2012 - 15 answers

## How to solve a complex statistics problem with a script?

In this game, you roll a number of six-sided dice to get a total. The total is either the highest single die result, or the sum of any multiples rolled, whichever is higher. For example: If I roll three dice and get a 3, 4, and 6, my total is 6. But if I roll a 4, 4, and 6, my total is 8, the sum of the two 4s. What I want to find out is the mean, median, mode, and standard deviation of the possible totals given N dice. How might I create a simple script to compute this?
posted by j0hnpaul on Nov 30, 2012 - 24 answers

## Practice Probability Word Problems

What great books or resources are there for practicing probability word problems such as for standardized tests like the GRE?
posted by Mr. Papagiorgio on Nov 8, 2012 - 3 answers

## What are the odds that two randomly selected people share the same bank PIN?

Statisticsfilter: Given available information about the distribution of self-selected 4-digit passwords (specifically banking PINs), is it possible to calculate the probability of two randomly selected individuals having the same PIN? If so, what're the odds?
posted by myrrh on Oct 27, 2012 - 15 answers

## How do I calculate the probability of a specific sum of repeated die rolls?

I'm looking to learn how to calculate probabilities for a multi-round dice game. I've researched this question some, and it looks like I might need to know how to use the multinomial distribution, but I can't find any good introductions. Please point me to the most layman-accessible educational material on this subject, and help me to help myself.
posted by Richard Daly on Sep 28, 2012 - 6 answers

## Recommendations for great books about probability and risk.

Recommendations for great books about probability and risk.
posted by inbetweener on Aug 17, 2012 - 18 answers

## Most 'realistic' rpg rules?

What are the most mathematically 'advanced' RPG systems? Pen & paper and otherwise?
posted by empath on Mar 14, 2012 - 24 answers

## Probability Question

Probability Question
posted by nickhb on Sep 3, 2011 - 15 answers

## Statistics filter: How do I calculate the keyspace size of a password?

How do I figure out what the size of this password's keyspace is?
posted by vmrob on Aug 27, 2011 - 10 answers

## Need help with a probability question

Can someone help with a probability question?
posted by caroljean63 on Jun 25, 2011 - 22 answers

## Picking the correct probability distribution

Which probability distribution should I use to model examination results?
posted by alby on Jan 13, 2011 - 13 answers

Has there ever been any research done on whether there is any correlation between spurts of adding contacts to LinkedIn or LinkedIn activity and someone changing job?
posted by MuffinMan on Jan 12, 2011 - 2 answers

## Is it 1 in 46,656?

Probability filter: after eating the TD turkey we play the Turkey game which consists of tossing six dice. The six faces of each die are carved with the letters that spells turkey. Each combination of letters earn a different score (for example T U is 5 points, 3 Ts wipe all the points earned, etc.) with the first TURKEY being the winner. How many tosses would you need to spell TURKEY?
posted by francesca too on Nov 29, 2010 - 15 answers

## How can someone guess the betting lines for a sporting event?

How does one guess sports betting odds, or determine at what point to place a bet on a sporting event?
posted by reenum on Apr 6, 2010 - 9 answers

## Conditional Probability

Stats-filter: Given a binary matrix, if I know the total number of ones in a given row and a given column, can I calculate the probability that a given position contains a one?
posted by chrisamiller on Dec 16, 2009 - 25 answers

## How many grandmothers will die in two months?

Actuarial / statistics geeks: a puzzle for you.
posted by Meatbomb on Dec 8, 2009 - 18 answers

## Not all random numbers are created equal

How do I get a controlled distribution of random numbers to fairly determine a start position.
posted by monkeystronghold on Oct 25, 2009 - 21 answers

## A Strange Bucket

I have a bucket containing N marbles: M white marbles and N-M black marbles. I need to grab a handful of marbles (n) and figure out the probability of having picked up m white marbles.
posted by Blazecock Pileon on Nov 6, 2008 - 16 answers

## Probability question (in need of code)

It's late, I'm tired, and I have a probability and coding question that's fairly simple.
posted by chrisamiller on Aug 13, 2008 - 10 answers

## What is a good sample size for determining whether dice are truly random?

How many times would I have to roll a standard 6-sided die to get a statistically representative view of whether it was truly random or not?

## Probability and Truth

Suppose you take a test for a rare type of cancer that affects 0.01 percent of the population. The test is 98 percent reliable. You get a positive reading. What are the chances you have the cancer? I read this probability puzzle today and the writer said the statistical chances of you having the cancer in this scenario are less than half a percent. I don't get it. Isn't the rarity factor irrelevant compared with the test reliability? Please explain.
posted by binturong on Apr 12, 2008 - 24 answers

## what's the probability distribution, kenneth?

for the statisticians: what probability distribution do I want to fit to my data, and how?
posted by russm on Jan 18, 2008 - 17 answers

## complex dice probability make head esplode

I need a tool to help me analyze the probability of certain events occurring regarding a pool of X dice for a game I am creating. See my examples below.
posted by DetonatedManiac on Dec 21, 2007 - 7 answers

## How many rolls 'till n values in a row.

Given a fair die with s sides, what is the expected number of rolls r before I get o outcomes with the same value v in a row? [Note this is emphatically NOT a homework problem; I just really want to know, feel like I should be able to figure it out, can't, and it is driving me nuts.]

## Philly or SF, which is safer?

Which city is safer: San Francisco or Philadelphia?
posted by rorycberger on Aug 10, 2006 - 14 answers

## Calculating probability with children

Looking for ideas for teaching probability to kids.
posted by carterk on Feb 6, 2006 - 16 answers

## Deriving formulas for Weibull distributions

Probability: A coworker is having an issue with deriving a few formulas for a Weibull distribution. Any pointers?
posted by TommyH on Nov 7, 2005 - 2 answers

## Need help with probability and statistics

In my exploration of poker odds and strategies, I've developed more programs for examining situations. I need help evaluating some of the probability and statistics involved.
posted by RustyBrooks on Jun 5, 2005 - 10 answers

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