| Subject | Date Asked | Expert |
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| probability | 11/16/2009 | ronny fisher |
Q: How are you? I know that if there are two events that both have a probability of 0.5, then the ...
A: andres - if the lift for A and B is 2, but for A, B and C it is 4, you can assume that C is somehow ...
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| probability | 11/15/2009 | ronny fisher |
Q: How are you? I know that if there are two events that both have a probability of 0.5, then the ...
A: andres - you are correct that for 3 independent events, each having probability 0.5, the ...
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| Error analysis in linear regression | 11/15/2009 | ronny fisher |
Q: I am preparing for practical round in Physics Olympiad, and now I have problems understanding the ...
A: chen - i am not familiar with ther expression you call delta m. in particular, i have never seen ...
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| Deciding which statistical test(s) to use | 11/9/2009 | ronny fisher |
Q: I have a dataset which contains two variables: observations of precipitation and precipitation as ...
A: steve - your question does seem to involve testing two hypotheses - and i think your formulation of ...
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| counting statistics | 11/5/2009 | ronny fisher |
Q: I have a question about standard deviation of a number. When we plate cells in biology and we decide ...
A: not being a biologist, i do not know what is meant by 'plating cells'. in order to give a cogent ...
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| New Studentized Range table? | 11/2/2009 | ronny fisher |
Q: Good day! I just want to ask if the table used for the Tukey's test which is the studentized range ...
A: mamoy - i haven't heard of 'new studentized range' tables per se. but there is an article that ...
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| Computing Margin of Error | 11/2/2009 | ronny fisher |
Q: This is a follow-up to a previous question for which you helped me, thanks again for that. The ...
A: dave - you are quite correct that the ME should also take into account the population size. the ...
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| non gaussian distribution | 10/22/2009 | ronny fisher |
Q: Just read another article by Nicholas Nasser Taleb about fat tail distributions. I'll just copy and ...
A: mark - the counter-intuitiveness you express about 'rare events' [which are called tail events in ...
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| non gaussian distribution | 10/21/2009 | ronny fisher |
Q: Just read another article by Nicholas Nasser Taleb about fat tail distributions. I'll just copy and ...
A: mark - sorry for the rejection email that went out to you. it was sent inadvertently. the ...
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| Standard Deviation | 10/16/2009 | ronny fisher |
Q: I'm taking a Business Statistics course. I'm trying to understand the concept of standard ...
A: davis - your question is more properly addressed to the instructor of the course you are taking - ...
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| Countings of a categorical variable at different time points | 10/14/2009 | ronny fisher |
Q: Fisher, maybe you can help me with the following data. I´m not sure how to analyze them. Here is ...
A: mara - i have an additional reference for you that may be of help. there is a book called ...
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| Game odds | 10/9/2009 | ronny fisher |
Q: I asked this question earlier today but did not get an answer. Thought I may have not sent it ...
A: ed - i can perhaps give you a push in the right direction to help you with your question. the ...
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| Polynomial Equations And Method Of Least Squares | 10/5/2009 | ronny fisher |
Q: First and foremost I have been out of school awhile and my memory of statistics is hazy at best but ...
A: barry - the attachment did get thru this time round. but unfortunately, it is of such poor quality ...
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| stat test | 10/4/2009 | Asmaa Abd Elhameed Ahmed |
Q: when using the mann-whitney ranking test, can I use it on both untransformed and log transformed ...
A: Mann-Whitney test used to compare quantitative not normally distributed data between 2 groups or ...
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| Probability | 10/2/2009 | ronny fisher |
Q: However, I'm 35 years old and looking to broaden my expertise into lean / Six Sigma. One of the ...
A: nathan - you've got a bit of a row to hoe if you want to become better acquainted with 6 sigma and ...
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| Polynomial Equations And Method Of Least Squares | 10/1/2009 | ronny fisher |
Q: First and foremost I have been out of school awhile and my memory of statistics is hazy at best but ...
A: barry - unfortunately, the attachment sent with your question did not seem to get transmitted to ...
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| sample design | 9/29/2009 | Asmaa Abd Elhameed Ahmed |
Q: can you explain the sampling design flaws in the make belief experiment below? I think he is ...
A: 1-first he should do sampling by cluster random sampling i.e.he should consider each of the great ...
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| Percentages & Statistics | 9/28/2009 | ronny fisher |
Q: This is not a homework question! I am just curious to know how to solve this with a somewhat simple ...
A: kenneth - there are lots of curious phenomena that one encounters in the realm of mathematics. for ...
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| Percentages & Statistics | 9/26/2009 | ronny fisher |
Q: This is not a homework question! I am just curious to know how to solve this with a somewhat simple ...
A: kenneth - your question involves simple algebra and is not really a probability question. having ...
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| Analyzing a survey | 9/20/2009 | ronny fisher |
Q: I have a temporary consulting job analyzing the results of a survey taken at a large organization. ...
A: dave - it sounds as though you do have a bit of a challenge facing you - to "just analyze it ...
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| The statistical significance of a difference of 1.2 years between the UK and US life expectancies? | 9/12/2009 | ronny fisher |
Q: Can you help me better understand the following issue? US life expectancy - 78.2 UK life ...
A: randy - there may be no statistical issues involved here. it all depends on how the life expectancy ...
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| The statistical significance of a difference of 1.2 years between the UK and US life expectancies? | 9/12/2009 | Asmaa Abd Elhameed Ahmed |
Q: US life expectancy - 78.2 UK life expectancy79.4 Source -United Nations World Population Prospects: ...
A: -to tell if there is statistically significant difference between the mean life expectancies we ...
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| Statistics | 9/12/2009 | ronny fisher |
Q: In the results of a research study, an author says that a group of treated patients was more likely ...
A: jeff - the abbreviation O.R. is not standard in statistics, as far as i am aware. it could mean ...
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| Lotto Probabilities | 9/10/2009 | ronny fisher |
Q: When looking at the probability of picking numbers for the lottery is there any statistical ...
A: randall - it makes no difference what system you use to pick numbers from week to week. if you ...
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| Statistics | 9/7/2009 | ronny fisher |
Q: Do you happen to know if there is a excel program that I can use to tell me what numbers come up the ...
A: chris - this is a somewhat outside my area of expertise. but for what it is worth, there is a ...
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| Exponential Distribution | 9/6/2009 | ronny fisher |
Q: I'm taking a course in computer simulation. I have a few questions on exponential distribution. I've ...
A: amril - the standard exponential distribution has the pdf f(x) = exp{-x} for x > 0. this ...
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| Exponential Distribution | 9/5/2009 | ronny fisher |
Q: I'm taking a course in computer simulation. I have a few questions on exponential distribution. I've ...
A: amril - the terms "exponential distribution" and "negative exponential distribution" mean the same ...
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| lotto probability debate | 9/4/2009 | ronny fisher |
Q: I don't play the lotto, but recently there was a MA lotto with a really big payout and two friends ...
A: megan - you are of course quite correct. any particular set of five numbers is as likely to occur ...
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| rolling a dice | 8/21/2009 | Jason Eisele |
Q: What would be the probability of rolling a 6 sided die say 8 times and getting a 6 once? Can ...
A: The first step to answering it is to observe the probability of throwing a 6 on just one roll. ...
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| F & t tests | 8/17/2009 | ronny fisher |
Q: In trying to verify a set of test results using the F & t tests. The F test which checks the ...
A: phil - you have to describe the F-test you are trying to carry out in a context. F-tests are used ...
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| standard dev | 8/16/2009 | statmaster |
Q: Suppose that the size of malignant breast lesions as observed on mammograms approximately follows a ...
A: Let the size of malignant breast lesions as observed on mammograms approximately follows a normal ...
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| F & t tests | 8/13/2009 | ronny fisher |
Q: In trying to verify a set of test results using the F & t tests. The F test which checks the ...
A: phil - what you point out is that tests based on small samples can have low power (= the chance of ...
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| Ouija Board Dice Test | 8/13/2009 | ronny fisher |
Q: I have a weird question for you. I am trying to come up with a way of testing the validity of an ...
A: jim - your answer is correct if you take the sequence order of the dice into account - as if you ...
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| Probability | 8/12/2009 | statmaster |
Q: I am trying to find out a suitable population size for a survey that I want to develop. I want ...
A: If your response variable is in terms of percent, you will get optimum minimum sample size when p ...
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| Probability at least one of three cards will come out on a three card flop | 8/11/2009 | ronny fisher |
Q: I play poker regularly. In Hold'em there is what is called the 'flop', three community cards which ...
A: rick - i understand your question to mean: what is the chance that at least one of the three cards ...
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| Time series data | 7/29/2009 | ronny fisher |
Q: What does it mean to used pooled data to find the average autocorrelation coefficient for sales ...
A: sally - time series is not exactly my thing. but i may be able to nudge you a bit in the right ...
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| Probability | 7/29/2009 | statmaster |
Q: I am trying to find out a suitable population size for a survey that I want to develop. I want ...
A: In order to estimate the sample size you require some preliminary information mainly regarding the ...
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| QA problem | 7/28/2009 | statmaster |
Q: A company claims that only 1 per cent of its products are faulty. If you took a random sample of 500 ...
A: This is an example of one sample testing of hypothesis. The null hypothesis is Ho:P=0.01 Agianst ...
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| please answer this question | 7/28/2009 | statmaster |
Q: in a recent survey of high school students, it is found that the average amount of money spend on ...
A: Let the average amount of money spend on entertainment each week foloes normal distribution with a ...
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| Comparison of ratios and percentages of 3 or more groups | 7/28/2009 | Asmaa Abd Elhameed Ahmed |
Q: we studied the effects of a drug given by four different methods in patients of asthma and measured ...
A: K-S test (kolmogrove-Smirnov test)is a test of normality It is used to explore the distribution of ...
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