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I am working on 4 different plants. I have the (RNA-Seq) data from sequencing. I look for two events E1 and E2, say, at certain positions in their genome. Let's say E2 is the common one and E1 is a special event. The positions I look for are identical across all 4 (in the genome). And let's say I see that the observati... |
I have a doubt regarding two tests:
Breusch–Pagan test, to detect heteroscedasticity in a series, and
Bartlett's test, to test for equal variances for samples from $k$
populations.
What are the difference betwen those two tests?
Are not those tests highly related?
How could a homoscedastic data give no homogeneity in... |
If I have a significant correlation coefficient of r=.80 between Variable A and B, I can work out the effect size (coefficient of determination) by squaring it, which is 64%.
I want to graph this in the simplest way possibe (given my non-statistical target audience). Can I use a 100% stacked bar graph for this purpose... |
I have a dataset with around 9000 cases, I'm running a factor analysis and I have found that 1100 cases are identified as being a multivariate outlier. Is it alright for me to got ahead and delete it?
|
I'm looking into a way to classify/categorize sentences into pre-defined categories (around 10-15). Yes, indeed sentences, not articles or paragraphs.
Given the average length of articles are not too long (2-10 normal pages) and number of articles (tens-hundreds) are relatively small, it is quite a small scale problem.... |
I have short daily time series (less than 4 years) representing sales and exhibiting two seasonalities (weekly and yearly) and I am seeking to identify outliers (not only data reporting errors but also particular events impacting the sales). Because of the presence of a trend and seasonalities, I think detrending and d... |
I often hear from statistical experts (including on this site) that simulation is the preferred method to calculate power for a clinical trial (rather than using traditional sample size calculation formulae).
I use Stata, and I was wondering if anyone can show me how to do this in detail?
For example, two scenarios:
1)... |
Consider translated Weibull distribution with probability density function:
$$
f(x ; k, \lambda, \theta) = \frac{k}{\lambda} \left( \frac{x-\theta}{\lambda} \right)^{k-1} \exp\left( - \left(\frac{x-\theta}{\lambda} \right)^k \right) \chi_{x \ge \theta}(x)
$$
Consider $ \mathbb{E}\left( -\partial_\theta^2 \log f(x; ... |
I want to plot $15$ random draws of Dirichlet distribution with $\alpha = 1$ and dimension $n=10$ in R.
require(MCMCpack)
alpha <- 1
draws <- 15
dimen <- 10
x <- rdirichlet(draws, rep(alpha, dimen))
I want an output similar to the following image. This image is from Prof. David Blei's Topic Modeling tutorial at KD... |
So I originally thought I would be able to solve this problem fairly easily with ANCOVA, but now that I've thought more deeply about it I realized it is not so simple.
Essentially we have a scalar response variable, $y$ which we want to predict using three variables $x$, $c$ and $g$. $x$ is a scalar variable (which tak... |
Sort of like the archipelago map in Age of Empires II
(But this is actually a real question that I do need for my exoplanet research)
|
Following my previous question (How to create a dataset with conditional probability?), now I want to create a dataset in R containing the information about TWO symptoms, and 1 disease.
Symptoms $S_1$ and $S_2$ and independent and conditional independent, so $P(S_1|S_2)=P(S_1)$ and $P(S_2|S_1)=P(S_2)$.
Suppose we have ... |
I just read that you can now buy a quantum computer (albeit that there has only been one sold so far!).
Will quantum computing have any applications in statistics?
{edit - for the purposes of the question let's assume that eventually quantum computers (in some form) will work}
|
I am investigating whether different reward conditions may affect task performance. I have data from a small study with two groups, each with n=20. I collected data on a task that involved performance in 3 different "reward" conditions. The task involved performance in each of the 3 conditions twice but in random order... |
Is there any literature on linear regression analysis where we require that our residuals are non-positive?
That is, we are interested in minimising:
$\sum_i \max(y_i - b x_i,0) $
EDIT: The motivation comes from Finance. I want to hedge a given portfolio of securities with value $P(t)$ with say $n$ hedging instruments ... |
I have network data of organizations and weighted links between these organisations, the weight indicates level of trade between these organisations. I have attribute files against each organisation relating to the number of environmentally friendly production technique they have initiated - for example, in response t... |
I'm testing the Homogeneity of Variances with Fligner-Killeen test using the function fligner.test in stats
On the chart below I have plotted the residuals that pass this test (p-value > 0.1)
Someone could tell how is it possible that these residuals pass FK test while having a significant movement around the center o... |
I am writing a program using high-dimensional volume (HDV) estimator to estimate entropy and mutual information for variable selection. Let $ D = (x^i_1, x^i_2, ..., x^i_M)$, N is the number of data points in the $M$ dimensional joint space.
The HDV estimators based on the equation as below:
\begin{aligned}
H(X) ≈ ψ(k)... |
I'm looking for sources of data related to Federal regulation and enforcement. Things like the following:
Size of Federal regulatory agencies (number of workers)
Number of pages of Federal regulations [total pages that are in force; not just new ones]
Number of enforcement actions brought by various agencies
Cost of ... |
I ran an ANOVA finding for example an interaction between gender and grade than I want to know in what grades boys and girls differ, but in many cases I find (adjusted) p-values of 0 and 1. How / why is this possible? Doesn't seem right...
as.factor(gender) 1 16 16.2 2.6377 0.104396
a... |
I am looking at a $\chi^2$ (crosstabs) test looking at interactions between types of dyads in an animal group. My categories are Male-Male, Male-Female, and Female-Female dyads in the rows and "Were Seen to Interact" and "Were Never Seen to Interact".
The matrix looks something like:
21 7
85 19
77 1
There is... |
Do you know any C# library or source code that can be used for ARMA / ARIMA forecasting?
|
I'm working in the area of natural language processing, to be specific I'm reviewing the parsers that take advantage of data-mining techniques.
I've read an introduction to natural language processing, specifically the maximum entropy approach by Della Pietra and others. In that paper, the authors explain that feature... |
I have corrected my alpha level using Šidák correction to take into account the experiment-wise error rate, as I am doing multiple correlation tests using the same data set.
My new alpha is 0.00056.
I tried using SPSS but the p threshold (alpha) seems to be either 0.01 or 0.05 and the p value of the correlation is giv... |
I have trouble proving the following fact in my econometrics homework. The lecturer said that I should merely look at my statistics books, but I cannot seem to find it anywhere! Thus, sorry if it is (too) ignorant a question.
Suppose that random variables $\varepsilon_{1t}$, $\varepsilon_{2t} \sim IIN(0,\Sigma)$ (i.e. ... |
I have two samples, A and B. I run the same model for A and B separately to obtain the estimates. I now want to test whether the parameters for models in A are the same with the parameters in B using SAS. Please advise.
|
I would pretty much appreciate if someone could explain the discrepancy detailed below.
Let's do a theoretical test first.
# make some test data with three levels and a vector of random numbers
test <- data.frame(ind = gl(3, 10), val = runif(30))
# calculate mean by "ind" (stored to a variable for pedagogic purposes
in... |
I am reading a book on time series analysis and I am having problems understanding the section about outlier detection.
The authors say that when you want to know whether at a certain time $T$ there was an outlier, you should use a certain test statistic and a test with size less than $\alpha$. But when you don't know ... |
I am planning to develop a course which I tentatively call as 'Quantitative Reasoning'. The goal of the course is to equip a typical undergraduate student with sound quantitative reasoning skills so that they can critically evaluate statistical and related quantitative claims they may encounter as part of their persona... |
The motivation for this question is from Finance. I have some market data (daily time series) for the price of some securities and I would like to generate synthetic versions of these which are statistically "similar" (in some sense) for testing trading strategies. Is there literature on this subject?
I was hoping ther... |
I have this series:
r <- c(14.1649994,17.3997831,32.8877030,6.1547551,6.3594748,101.9584077,196.8411517,23.8292043,11.7583992,2.2915478,5.5088687,16.8188390,2.3077979,2.6666377,2.0955362,0.9319688,0.6688078,1.0523184,6.8158264,13.1813211,17.8467944,1.9876636,7.0219306,3.9272217,4.3325448,7.8778125,1.1878058,1.7207762,2... |
I have run a very long computation in WinBUGS (million iterations) using the R2WinBUGS package from within R:
bugs.object <- bugs(...)
but the R crashed. How do I reload the bugs.object into R again without running winbugs again? I tried this (I have 3 chains):
out <- read.bugs(paste("coda", 1:3, ".txt", sep = ""))
b... |
Let $X_1$ and $X_2$ be independent, normal distributed random variables with equal mean $\mu$ but non-equal standard deviations $\sigma_1$ and $\sigma_2$.
Suppose I know $\sigma_1$ and $\sigma_2$ and I have $n$ samples $x_{11},\ldots,x_{1n}$ from $X_1$ and m samples $x_{21}, \ldots, x_{2m}$ from $X_2$, what is the best... |
I'm interested in what exactly sentences like this mean:
In the former case, participants correctly chose the larger city in
55% of the pairs, in the latter in 54% of the pairs, both rates
significantly different from chance.
Is it basically just that its significantly different from 50%?
UPDATE:
Here's another ... |
I am writing with questions about a study I am helping with:
Two “raters” will score athletes subjectively from 0 to 3 (3>2>1>0) on each of 10 skill performances. Scores will be summed to a maximum of 30, and the total bracketed into approximately three categories for comparison with regard to knee injury incidence. ... |
I am looking to fit a Cox proportional hazard survival model. Looking at the K-M curve (below) for one variable (with 2 categories) it appears there is a change in hazard ratios at around day 110. I was thinking of modeling this with a change-point model.
I'm having trouble implementing it. I have defined days_ind ... |
I hope I am at the right place, I was pointed here for further feedback from stackoverflow.
I would like to ask you, whether it makes sense to you what I am trying to do in order to optimize my model.
Here is my problem
I am building ranking, based on Elo approach. I have extended it with 2 additional parameters (basic... |
I have a data set comprising of responses from approximately 385 people on several variables such as their shopping habits, mode of transport to the shopping centre etc. I want to do Pearson correlation on the variables (by age, gender, income level etc. of the respondents).
Is there any rule that says what would be t... |
I believe I have rather simple question but I would like to make it right.
I have already asked question, however I am not sure whether I did everything correct or there is a mistake in the answer (probably the first one, but still I cannot find it).
To make it short:
I would like to check how well my model predicts o... |
In my dataset we have both continuous and naturally discrete variables. I want to know whether we can do hierarchical clustering using both type of variables. And if yes, what distance measure is appropriate?
|
I have a set of data where each data consist of $n$ different measures. For each measure, I have a benchmark value. I would like to know how close each data is to the benchmark value.
I thought of using the Weighted Euclidean Distance like this:
$\hspace{0.5in} d_{x,b}=\left( \sum_{i=1}^{n}w_i(x_i-b_i)^2)\right)^{1/2} ... |
I have a number of set of data points. For each set I have done linear regression to find the lines of best fit for the data.
I hypothesise that the gradients of all the lines of best fit should be zero.
I took the average and standard deviation of all the gradients and these are the values I calculated:
mean = $5.72 \... |
I'm processing some data that requires binning before it goes through a regression algorithm. The script is in Python and uses the Numpy histogram function, but the code should be self explanatory. For reference, histogram outputs either an array containing the integer number of points in each bin, or you can weight ... |
I'm looking for a method to determine the likelihood that two percentages from independent groups are EQUAL. In this case I'm looking at the likelihood of symptom improvement from patients gathered through two different methods (one traditional double-blind study and one from an online enrollment).
So if in the traditi... |
This questions might sound stupid, but... is it correct that random effects could apply only to categorical variables (like individual id, population id, ...), e.g. say $x_i$ is categorical variable:
$y_i$ ~ $\beta_{x_i}$
$\beta_{x_i}$ ~ $Norm(\mu, \delta^2)$
but from the principle the random effect cannot apply to con... |
Functions I'm familiar with include scale from base R, rescale from ARM.
Perhaps the best way would be to use some variant of apply, specifying one or more variables to use as grouping variables.
|
I am curious about the consequences of changing the order of the explanatory variables in a binary logistic regression. In a recent series of logistic regressions I ran in SPSS, I found that changing the order of the explanatory variables ($z, y, x$ instead of $x, y, z$) resulted in different coefficient values and sig... |
I'm looking to generate as much interesting data as I can from some 2on2 basketball games.
The only data I have recorded is the players on each team, and the final score.
What interesting things can I learn from this data? I'm interested in what I can learn about the individual players, as well as the teams and player ... |
I come across a practice where the logit (Intercept + beta* variables) is once again input as a independant variable in a single variable logistic regression against dependant variable to get intercept ($I$) and a beta ($B_0$). Finally, probability is calculated: $\frac{1}{1+e^{-(I+B_0\text{logit})}}$.
Why is this done... |
What is the difference between each of them?
this wiki page - http://en.wikipedia.org/wiki/Latin_hypercube_sampling says that:
"In Orthogonal Sampling, the sample space is divided into equally probable subspaces", which to me sounds like a property of low discrepancy sequence.
|
If I wanted to answer the following question, is there any website which will allow me to do it? (or has it already been done?)
What percentage of people with Computer Science Degrees aged 30-40 are Married?
What percentage of people with other degrees aged 30-40 are Married?
Surely somewhere online there is a site w... |
I have 4 sets of data points and for each I want to see how much these values vary from zero.
I used the tool for calculating the results of the test on this page but I'm having trouble understanding the results.
The results for my 4 sets of data points are:
W+ = 3, W- = 12, N = 5, p <= 0.3125 for 101 ... |
I'm trying to find the estimates for $alpha$ and $beta$ of the beta distribution (red curve) that will fit the black curve (empirical) better.
I have a function that finds "non-parametric" inverse cumulative function of my data (boot.mean). I would like to find a distribution that would fit. So far, I think cumulative... |
Possible Duplicate:
How to interpret the divergence of Fisher information expectation?
Consider translated Weibull distribution with probability density function:
$$
f(x ; k, \lambda, \theta) = \frac{k}{\lambda} \left( \frac{x-\theta}{\lambda} \right)^{k-1} \exp\left( - \left(\frac{x-\theta}{\lambda} \right)^k \ri... |
I'm newbie and bit lost... Can someone help me read this result from SPSS 1-sample Kolmogorov-Smirnov test (poisson distribution).
SUBKEY1 SUBKEY2 SUBKEY3 SUBKEY4 SUBKEY5
N 128 128 128 128 128
Poisson Parametera,,b M... |
Is it possible to predict values of variables in a matrix Y from values of variables in a matrix X, ie. using canonical correlations since some variables are correlated among these two matrix?
X and Y contain variables for the same individuals.
If possible, I would like an example using R.
Edit: the aim is to fill miss... |
I have been searching for the answer for a problem with confidence intervals for a long time now, so I hope someone can help!
The two psychological papers below performed the same analysis, regressing irregular word reading onto nonword reading for controls, and plotting these regressions with 90% confidence intervals,... |
I have (censored) time-to event data for subjects in four groups. I would like to do something like a logrank test, but the survival curves do not satisfy the proportional hazards assumption. I think I have heard that the consequence of a prop. hazards violation is loss of power to identify differences between surviv... |
Possible Duplicate:
R^2, ESS, TSS - how well my model predicts outcome
I have already posted longer version of my question, however I have obtained no answer, so I will try to make it simpler.
I have calculated ESS and TSS for many cycles and my R^2 values where from 0.99 to 1.05. How can I interpret this? Do I have... |
I have problems regarding analyzing dummy variable using fixed effects in Stata. I am doing research on impact of climate change in food grain production.
Much previous literature states that panel data use fixed effect regarding this types of analysis, as others I also follow the same things but I have to take soil va... |
In a questionnaire study, we asked respondents to express their attitudes towards how different winter climate factors such as snow, slipperiness might affect their choice to walk and cycle to work. The sample composed of 500 individuals and answers were in form of 5 scales rating form very negative to very positive (o... |
In case, one wants to do some inference with one-sample Likert-type data, what tests could one use? Signed Rank Test?
|
You sample N of N items with replacement.
How do you calculate the expected percent not sampled from original population N?
Extra Credit: Generalize to sampling k of N items with replacement.
|
I am an R noob who is required to do various kinds of analysis on large data sets in R. So while looking around this site and elsewhere, it appeared to me that there are a lot of esoteric and less well known issues involved here - like which package to use when, what transformations to (not) apply on the data etc.
I a... |
There seem to be two different algorithms for comparing three or more survival curves using the logrank test.
Algorithm A. Found in books by Altman and Machin. Computed by GraphPad Prism. This method uses an algorithm that is easy to understand, computing chi-square from the discrepancy between observed and expected n... |
State-space models are represented by a state equation and an observation equation (or system of equations to be more precise). These equations are parametarized by components including a transition matrix (FF in some notation) and GG respectively.
These component matrices can have large dimensions. Indeed, the log-lik... |
I am a stats novice so I'm sorry if my jargon is a bit off.
I have several large samples of workers in different demographic categories from two different fields A and B. I want to compare the proportion of people in each sample (not of equal size) and try to figure out if there is a difference in the distributions th... |
Do I have to use Bonferroni's or Holm's corrections?
Please see this previous question for my example data and the design. (Shortly, I have three or more dependent groups.)
|
I have a quick question about the correct way to describe variance functions when seeking to cope with heteroscedasticity. As I understand it the statistical error of a model represents the departure between a sample and the true function value. In practice we don't usually know the true function value. In contrast, re... |
Control charts are all the rage at my company these days. Our "data analysts" (quotes are on purpose) are putting control limits on almost all graphs that they produce. The other day we were looking at some graphs of calls into our support call center over the last year. We have measurements of the number of calls for ... |
I'm looking at developing a mixed effect model for repeated measures of blood pressure using two different techniques. I have been discussing the benefits of mixed models over repeated measures ANOVA on SE previously. Only problem is that I'm finding the literature on mixed models in R is based on a starting point qu... |
I would like to validate the standard deviation which a model reports, because I think it is underestimated, because in the procedure some model selection is involved.
After running the model on a validation set, it became clear to me that the standard deviation were indeed grossly underestimated.
I could not really f... |
Would like to know how confident I can be in my $\lambda$. Anyone know of a way to set upper and lower confidence levels for a Poisson distribution?
Observations ($n$) = 88
Sample mean ($\lambda$) = 47.18182
what would the 95% confidence look like for this?
|
I am trying to model the time lapse between when a user sees an ad and when they call the advertiser (presuming they do). I have two issues - part of the data seems exponential, but I am wondering if there is a similar distribution with an extra parameter because I cannot quite get it to fit. Also, the peak does not ... |
My friend and I want to do a hands on tutorial on Bayes theorem for the Seattle LessWrong group. Neither of us have done this before, so we're searching for prior art; techniques that other people have tried before and descriptions of how they turned out.
What are good techniques and resources for teaching bayes theor... |
Now, $X$ is my IV and $Z$ is the DV. In my analysis, I also have a mediating Variable $Y$. The significant $\beta$ while doing MRA between $X$ and $Z$ is -.85. Other conditions being satisfied, when I had MRA between $X$ and $Z$ with mediating variable $Y$, the sig. $\beta$ is -.32. Here if we do not consider the nega... |
So I have this joint dist
$$f(x,y) = \frac{1}{2\pi}\exp(-\frac{x^2}{2} - \frac{y^2}{2} + x^2y - \frac{x^4}{2})$$
I'd like to find $f_x(x)$. So I know that means I need to integrate function wrt y. So my strategy is to pull out whatever terms I can so some of it will look like the normal dist then it'll integrate to ... |
I'm trying to implement a naive Bayes classifier to classify documents that are essentially sets (as opposed to bags) of features, i.e. each feature contains a set of unique features, each of which can appear at most once in the document. For example, you can think of the features as unique keywords for documents.
I've... |
For an experiment I'm analyzing, I took many measurements of many different values. (To make it concrete, let's pretend I measured the height of people from many different age groups -- I have the height of ten 20-year-olds, ten 21-year-olds, ten 22-year-olds, etc.)
I'd like to demonstrate that the variance of all my r... |
I am interested in assessing the divergence, or similarity or dissimilarity of 2 datasets that are the results of 2 different lidar instrument measurements. Each dataset has over 90,000 values and they do measure a continuous variable, let's say altitude. Each dataset has a bimodal distribution with a long tail on the ... |
Consider the following simple set-up. In the interval $[0, 1]$ we are observing the realizations of independent normally distributed random variables at times $t_1,\ldots, t_N$. The r.v. $X(t)$ has mean 0 and standard deviation $\sigma(t)$, where all is known about $\sigma(\cdot)$ is that it is smooth, say at least dif... |
Maybe let me first describe the real world application of my problem before going to a more mathematical model.
Suppose I have a system that measures my current position up to an unknown error (let's say this would be a GPS-device). At every point that is recorded I also save the accurate position obtained by other mea... |
I am testing a variety of models to produce 1-month ahead predictions of US Recessions. To benchmark these models, I want to build a naive recession model. My first thought was to use the current state of the recession variable to predict the next state of the recession variable:
library(quantmod)
getSymbols('USREC',... |
I see that $E(X)$ and $\mu_x$ are used to refer to the mean of some distribution or variate, but I am not clear on what circumstances each is appropriate.
$E(X)$ seems to always be more often in the context of a random variable
$\mu_x$ seems to appear when referring to the mean of some distribution. for example my book... |
I have an experiment with 3 biological factors (dev, dev_stage; reg, brain_region; gen, gen_type) plus a batch factor (bat, batch). Unfortunately I have only rather superficial understanding of ANOVA or other statistics, so I'm not sure what is the right formula for my data (I'd consider all 3 biological factors plus t... |
Given that I have 4 banks (bank A, B, C and D) and the data (stock value) I have is from 1998 to present year.
At the year 2002, Bank A acquired Bank C. At 2005, Bank A acquired Bank D. Until there is only 1 surviving Bank (A) at present. I want to test whether each merge was effective (in terms of Bank A) or not.
I c... |
Suppose, I have a correlation coefficient of 0.6234 between Variables A and B, on a sample size of 20. My alpha threshold is 0.05. I want to do a power analysis on this result.
I found a calculator but it is asking for "Correlation p H1".
Does this refer to the correlation coefficient "r" (0.6234 as above) or the p val... |
I think this is simple, and I am wrong-thinking it....
t-tests are used to test the null hypothesis that the means are equal;
$H_0 : \beta_1 = \beta_2$,
$H_1 : \beta_1 \neq \beta_2$
But I want to test the other way around;
$H_0 : \beta_1 \neq \beta_2$,
$H_1 : \beta_1 = \beta_2$
Do I just swap the hypotheses and 1-p t... |
I am having a hard time with what seems to be a very basic research design issue.
The study has 3 variables:
Self-control and adjustment are the main ones, since they were measured in pre and post tests, before and after a year long social and emotional program in two different high schools. (I guess this part of the... |
I want to analyze some data of a questionnaire on presence (I deal with experiments on virtual reality).
The questionnaire was provided twice to particpants performing the experiment, after each of the two provided conditions.
The 6 questions of the questionnaire were evaluated by participants on a 7-points Likert sca... |
The help page for Prism gives the following explanation for how it computes the prediction bands for non-linear regression. Please excuse the long quote, but I am not following the second paragraph (that explains how $G|x$ is defined and $dY/dP$ is computed). Any help would be greatly appreciated.
The calculation of... |
While studying logistic modeling, I read the following statement
The fact that only odds ratios, not individual risks, can be estimated from logistic
modeling in case-control or cross-sectional studies is not surprising.
I do not know what do the "case-control" and "cross-sectional studies" stand for in the stati... |
I am performing multiple regression analyses and I am not sure whether outliers in my data should be deleted. The data I am concerned about appear as "circles" on the SPSS boxplots, however there are no asterisks (which makes me think they are not 'that bad'). The cases I am concerned about do appear under the "casewis... |
I need to check the homogeneity of variances on the residuals of a linear regression. I read that Kruskal is also good without assuming a normal-distribution. But I don't know if it's good in my case. I'm doing a linear regression of two vectors of prices(stock prices). I also checked the normality with Anderson-Darlin... |
I'm creating an app that logs daily data from my users.
Data includes:
waist circumference, weight (Quantitative data)
certain conditions like psoriasis, migraines, fatigue (Qualitative data rated from 1 to 5).
Showing charts for each entitiy is fairly easy.
How can I take both data and show an overall improvemen... |
In the research, both autocorrelation and heteroskedasticity are detected in panel data analysis. I can solve them separately in stata with command "xtregar" and "robust", respectly. However, I cannot find a way to solve both problems at the same time.
If possible, please show me how to repair autocorrelation and heter... |
What are the available options if I want to perform a scoring task on a set of observations that: a) have a set of variables connected to them and, b) each round I get new information about the success of the latest round.
What I mean is, I start with a normal scoring task: Using the available training data I want to r... |
If one considers a hypothetical RCT, say a total sample size of 300, separated into three strata based on surgical procedure (open surgery, closed surgery, or combined procedure). Blocking in groups of 2 will be done within each stratum.
When generating the randomization sequence, obviously one cannot know ahead of tim... |
I'm looking for some advice for where to start on this problem. Let's say I have sales transaction data from a number of different retailers that all sell the same products. Even though they are selling the same products they all identify them a little bit differently. For example for one particular product one retaile... |
Like if I was given a P(A) of .5 and a P(B) value of .4 how would I get the minimum of the P(A∩B)?
|
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