probability

The above post led me to write a little WebApp to play with to see the result of coin tosses varying from 10 at a time to 10,000,000 at a time So you can set the number of coin tosses you would like to see the results for and then tell the app to flip the coin that many times.... it will give...

It's no wonder people don't trust statistics. It seems far too many are statistically innumerate. Measuring Risk Literacy: The Berlin Numeracy Test http://journal.sjdm.org/11/11808/jdm11808.pdf The Berlin Numeracy Test was found to be the strongest predictor of comprehension of everyday risks...

So... in South Africa yesterday, the Powerball results were interesting, and when they are this interesting, a lot of people begin to question whether there are some shenanigans going on. The powerball here is structured as follows: Select 5 balls from a pool of 45 Select 1 powerball from a...

Long story short Lotto power ball built over several weeks to 38 mill They said the chances of winning were 36 mill to one Two people got it. Are the chances of a person getting the right numbers 36m-1 at the same time as another person gets them 36m-1, higher than 36m-1, or still just...

So I've been going back and forth with a friend of a friend online regarding the Monte Hall Problem. It has devolved into disagreements about probabilities and I'm having a hard time. He has gone into 'actual' and 'perceived' odds. My latest example is 'When you dive by my house, I'm either...

This might be boring If so I apologise Probably the most common thing with lottery some people seem to not get is the chances of it being the numbers 1,2,3,4,5 are the same as any other group of numbers, and assume it is not possible. This week ours was nearly the next best thing 3, 5, 7, 9...

This post has me wondering. Without question, everything that goes into a coin flip is physical and measurable - force, air currents, uneven weight of the sides, etc. In theory, it could all be modeled. Could we do it in practice? Is it foreseeable that we would ever be able to measure...

Probability in her various guises comes up a lot at ISF. We cite statistics and percentages, mention things like relative risk, and point to studies with p values to justify our positions. We invoke Bayes and Occam. But I'm often troubled by just what probability is supposed to mean. Is it, for...

I've just posted this at SBM, but I suspect the "hard science" members of JREF might be better placed to answer my question. I wonder whether the question should be phrased like this: there is a prior probability that a medication works, do uncontrolled anecdotal accounts of positive benefit...

I know that in a Bernoulli Trial situation, probability can be defined as the relative frequency of successes if the trial is repeated indefinitely. But how do we define probability in one-off situations (for example, predicting that a certain event will take place at a certain date)? The...

A probability can be from 0 to 1, but what about a possibility? That is, is a possibility either 0 or 1? Or can a possibility also be from 0 to 1? Note: I am not talking about conditional probabilities, or am I?

I didn't want to derail the other current Lotto thread so have started this thread to ask . . . What is the better bet? One attempt at winning with 3,838,380 to one odds for the attempt, or ten attempts at winning with 38,383,800 to one odds for each attempt? Or are they both the same?

For years, I've been telling people that it's as likely for you to get the above numbers as something like 35,32,18,16, 28, 21. People can't seem to believe it. Is this actually the case, or am I making a fool of myself?

A friend and I recently tossed back and forth on a hyptotheical issue. Let's say you are an organization like the JREF and you test people who claim to have psychic abilities. What protocol would you advise for a test of telekinesis? Here's the issues: 1)The test has to be fair both ways...

I've just taken the Bang goes the Theory Big Risk Test. All answers were multiple choice. One of the questions was as follows: I picked the answer nearest to the one I calculated from those available (95%, 83%, 17% and 5%, IIRC): The value I calculated was... Have I missed something or...

In this very strange thread, forum member Epix issued me this challenge: So, I throw it out to you. Do you agree that something that is very likely is exactly as possible as something that is very unlikely?

Is a sequence of 100 heads in a row literally impossible to get without cheating? This was discussed in another thread but a mutual decision has been made to start a new thread about it. http://www.internationalskeptics.com/forums/showthread.php?t=200394 My position is that it is entirely...

A False Coin - hopefully the link works - I wrote considering the oft-repeated argument (by theists) that the atheist cannot know there is no God because the atheist has not been everywhere. This questions how one can be certain of a negative result only through a finite amount of negative data...

I came across the following podcast recently: Science Show - 2010-06-26 Saturday, 26 June 2010 12:00 AM Radiolab: Stochasticity This Radiolab looks at the role chance and randomness play in sport, gambling, and even the cells in our own body. Radiolab is a production of WNYC in New York City...

Today, my psychology professor asserted that people can accurately predict random events roughly 60% of the time (he qualified this statement by saying that the actual figure lay around 57% and he was rounding). I asked him for an explanation of this claim, and in the following class...

I realise that the lottery banner which the site's home page carries bears a disclaimer, but for the first time I actually read it today. It said that I am a winner, and that I am the 12,860,116,513th visitor to see that banner. So there have been nearly 13 billion winners. Leaving aside how...

I just now came upon a reference in the latest issue of Crypto-Gram to this article by a blogger named James Devlin. It's an interesting discussion of a paper titled Dynamical Bias in the Coin Toss. There's one particular point in this article that bothers me and that I'd like to discuss here...

I have a question regarding prior vs posterior probabilities -- can it be said that all prior probabilities are in fact 0.5, since any knowledge at all could be argued to contribute to only posteriors? For instance, if I roll a typical die, is it valid to say the prior probability of rolling a...

There are a group of people that know a secret. The probability that any one person leaks the secret is 0.03. a) If there are 2 people in the group, what is probability that someone leaks the secret? What if there are 5 people in the group? b) How many people in the group do you need to...

OK, I'll await the howls of derisive laughter, but bear with me... John Maynard Keynes is much in the news at the moment as we try to spend our way out of financial catastrophe. An anecdote of him reported in a news bulletin a few days ago said that he was staying in Monte Carlo and heard that...

I have been thinking about this one for a while now: On Deal or No Deal, if a contestant gets down to two cases and the top prize is still on the board, what is the probability that the case he or she holds contains the top prize? My first thought was to relate this to the Monty Hall puzzle...

For your reading pleasure.

No events in life have a probability of 0 or 1 of occurring. Statistical information is rarely available about us as individuals, so we have to rely on averages of groups and assume we share many of the significant characteristics of a particular group if we wish to use the data in our...

and how is it "random"? Or does the phrase "random variable" mean something different that a combination of "random" and "variable" (i.e., a variable that is random, can take on random values)? Note: I do have some knowledge of probability theory beyond that which is taught in primary and...

Given 3 reels on a slot machine and 14 symbols on each reel. What are the odds of: 1. Any pair 2. Any triple? Ta.