A brief numerical description of a set of data.

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5
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0answers
149 views

A tricky question about correlation [duplicate]

$X$, $Y$ and $Z$ are three random variables where their pairwise correlations are the same, i.e., $corr(X,Y)=corr(Y,Z)=corr(X,Z)=\rho$ what are the possible values of $\rho$? I was asked this in an ...
0
votes
2answers
27 views

Would this situation be a ratio of 1/5 or 1/10?

Hypothetical situation that I'm trying to use for understanding some criminal statistics. Let's say there is a city with 10 banks. One criminal robs two banks before being arrested and placed in ...
1
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1answer
50 views

assumptions made for a normal distribution- a interview question

I was asked in my interview: What assumptions can you make? Why and when? (i.e When is it safe to assume "normal"). Can some one answer this .
6
votes
0answers
51 views

When would we use tantiles and the medial, rather than quantiles and the median?

I can't find definitions for either tantile or medial on Wikipedia or Wolfram Mathworld, but the following explanation is given in Bílková, D. and Mala, I. (2012), "Application of the L-moment method ...
2
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0answers
22 views

Is this a valid use of “positive predictive value”?

So here's your typical table for evaluating the performance of a diagnostic test: Gold standard result ...
0
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0answers
8 views

What effect do outliers have on standard deviation and the IQR?

I understand that they will both sorta increase, but if i remove them how will the bulk of my data change? for example in a boxplot/ histogram
0
votes
0answers
12 views

How to find the probalities of a,b,c (mutually exclusive events) when i turn the problem into three binary classification problems?

I am using scikits linear logisitc regression to classify three events a,b and c. it works better (score) when i convert them into a binary classification model. such as: 1. M1 classifies a or b 2. ...
4
votes
0answers
87 views

Caclulating standard errors for generalized least squares without raw data (just sample means and covariance)

I have a question very similar to the question asked here: is it possible to calculate standard errors (specifically, the standard error of the intercept) for generalized least squares regression ...
6
votes
3answers
168 views

Will two distributions with identical 5-number summaries always have the same shape?

I know that if I can have two distributions with the same mean and variance be different shapes, because I can have a N(x,s) and a U(x,s) But what about if their min, Q1, median, Q3, and max are ...
1
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0answers
4 views

Analysis of possibly correlated small sample data

I'm doing an experiment where I'm imaging 3 groups of 5 rabbits (total = 15 rabbits) using 4 different machines at 4 different anatomical locations to see if a radio-opaque material is visible in all ...
3
votes
1answer
94 views

Estimate mean & standard deviation of set S if I know stats of an inner set and outer set

Suppose I have sets $S_1\subset S_2\subset S_3$. I know exactly the size, mean, and standard deviation of both $S_1$ and $S_3$ and want to estimate the mean and standard deviation of $S_2$, where I ...
5
votes
2answers
126 views

Standard error of regression coefficient without raw data

After searching here: Perform simple regression without raw data I am still curious about this. Is it possible to derive the standard error of a regression coefficient from summary data alone? ...
0
votes
1answer
20 views

Using stat methods on summary statistics

Is it ok to use statistical methods on summary statistics, as they're random variables? I ran into an interesting problem while working with a client, but will try to keep it very general as the ...
0
votes
1answer
36 views

Log form of variables and descriptive measures

Because of larger values of variables, I did a log- transformation in my dataset. Now I want to give a descriptive table regarding my variables like mean, max, min, median, skewness, kurtosis. Can I ...
0
votes
0answers
28 views

What are the quantitative methods alternative to Meta-Analysis?

What are the alternative statistical quantitative synthesis methods for combining studies, if we can't apply meta-analysis because of the heteronegeity or the shape of the data, for the data set of ...
0
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0answers
46 views

Which method should I use to combine the data of my studies?

I want to make a meta-analysis on household consumption expenditures elasticity data. In these studies that I've got; methods and regions and etc. varies according to studies. But at last, the results ...
0
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0answers
40 views

What summary statistics can be applied to the results from a multiple choice question?

I have a list of answers given for a multiple choice question. For multiple choice I mean that from a set of possible answers given, more than one can be chosen. For other answers with single choice I ...
3
votes
0answers
78 views

Partial correlation and multiple regression controlling for categorical variables

I am looking through the linear association between variable $X$ and $Y$ with some controlling variables $\mathbf{Z} =(Z_1, Z_2, Z_3, \dots)$ One approach is to do a regression $E(Y)= \alpha_0 ...
1
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0answers
19 views

Calculating overall variability over multiple datasets

I am trying to determine a way to measure the consistency of transit hours performed by transportation providers over their entire portfolio of shipping routes. For example, if a company has 3 ...
4
votes
1answer
29 views

How to represent data graphically in which a respondents can choose more than one group?

I am analyzing a survey in which one of the questions was (What is the industry segment of your company?) and the respondents can choose more than one category. I have used a pie chart to represent ...
1
vote
0answers
31 views

How did they do this analysis? (weighted proportions)

I've read with interest the report by Ayanian et al "Racial and Ethnic Disparities among Enrollees in Medicare Advantage Plans" [1]. They have estimated adjusted proportions of individuals that ...
3
votes
3answers
193 views

glm in R - which pvalue represents the goodness of fit of entire model?

I am running glms in R (generalised linear models). I thought I knew pvalues - until I saw that calling up a summary for a glm does not give you an overriding pvalue representative of the model as a ...
0
votes
0answers
18 views

How to implement Exponential Histograms

I am having trouble in understanding the concept of exponential histograms. They are known to be much efficient for maintaining statistics. I have read it in this article but cant understand how they ...
2
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0answers
13 views

Quantitative tail sizing

What is the most generic way of deciding whether the tail of a dataset is long or short? In other words, what would be the unit-free summary metric m that could be ...
3
votes
1answer
23 views

How to prove that the permutation of the points are the minimal sufficient statistics for Cauchy distribution?

I see this everywhere that the permutation of the samples $X_{(1)}, ..., X_{(n)}$ is the minimal sufficient statistic for the Cauchy distribution [1]. It is clear that it is a sufficient statistic,but ...
-1
votes
1answer
53 views

Appropriate statistical analysis to use

I have built and tested a computer application, which involved two participant groups (Group-A with existing knowledge of databases and Group-B without knowledge of databases). I was required to apply ...
3
votes
1answer
43 views

Is there a way to characterize the position of a point in a distribution that takes higher moments into account?

When summarizing a location in a distribution, we can take the mean into account by simply calculating $x-\mu$. We can take the standard deviation into account by calculating a Z score ...
2
votes
1answer
65 views

Mann-Whitney U test when only summary data (mean, sd, sample size) are available

When raw data is not available, which normally occurs when we obtain our data from different scientific papers, how is it possible to perform a Mann-Whitney analysis to test whether two samples are ...
1
vote
1answer
24 views

What's the meaning of 'statistical break'? And how to calculate it?

I am reading a paper named "EPRI-GTC Overhead Electric Transmission Line Siting Methodology", and in this paper the author uses "the first statistical break in its histogram" to determine the corridor ...
1
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0answers
26 views

A walk through my datas

I wish to study the effect of a categorical factor on the rate of increase of some parameter Y along a given X explanatory variable. My datas looks like: ...
1
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0answers
27 views

Interpreting summary output in R [duplicate]

I'm fitting a linear model to a dataset. I've reduced the model from 7 variables to 3 and as part of that I've transformed one of my variables (wt) in order to get a better fit. For my final model, ...
1
vote
1answer
38 views

measure for jobs/complaints ratio

I have a number of jobs in a database which can receive complaints. A job can receive several complaints and a job has an associated supplier. I would like to identify the worst performing suppliers. ...
0
votes
0answers
10 views

how to take the sum in using 3 point scale

I have conducted a survey through a questionnaire which consists of 45 questions grouped under 6 independent variables and apart from this i have taken 3 dependent variables which i want to regress ...
1
vote
1answer
52 views

What statistical analysis should I use for my study?

In my psych class we were testing to see if groups of men or groups of women would be more helpful in an emergency situation (we are testing for the bystander effect), and we are testing to see if ...
0
votes
1answer
42 views

regarding the explanation of interaction plot

I was trying to draw an interaction plot for two predictor variables as follows: interaction.plot(xtest[,2],xtest[,8],y) I got the following plot. I do not know ...
0
votes
1answer
36 views

Average time series data (summarize) increasing slope of line

We are working on time series data forecasting. Our input data set is large, so thought to average two consecutive data points and reduce it to half the size. But we have observed that average values ...
0
votes
0answers
43 views

difference between machine learning and stastitical technique [duplicate]

Is there any difference between machine learning and stastitical techniques. I have searched a lot some researchers say that there are some overlap some are saying there is no difference.Can you give ...
1
vote
0answers
48 views

Should descriptive statistics on percentages data be weighted?

I'm trying to put together descriptive statistics for a set of differently sized groups of students. For each group of students, let's say I know the # of students who are left handed. I'd like to ...
1
vote
1answer
28 views

Best statistical method to show different performance week over week

I am trying to get best statical method to show performance of accumulative revenue by customer compare week over week. Currently I have about over 100 customer charts compare by hour from same day ...
0
votes
0answers
18 views

Getting estimates of hospital specific stroke admissions data

I am analysing a small data set on stroke process of care gathered from public sources but don't have access to hospital specific emergency stroke admissions over a period of time data except for ...
0
votes
0answers
8 views

What are the Outputs of analytic process

I am trying to understand the different types of output generated as a result of the analytic process. If my customer does not understand Linear regression, Random Forest, then what is the best way of ...
0
votes
0answers
22 views

regarding the statistics to test the impact of some subset values on a given variable

For a given variable, there is a set of values. We know that these values can belong to different clusters. For instance, a lot of values center around a small value while other values center around a ...
0
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0answers
70 views

How to measure defense and attack of a soccer team using goals

i've been trying to come up with a way to measure attack and defense of a team in terms of goals scored and received. The only thing that has crossed my mind is to divide the number of goals ...
1
vote
1answer
47 views

How to quantify the importance of a win in soccer?

I've been thinking lately that the "importance" of a win in a soccer match depends on how good the opponent is. Let's take the spanish league for example. You have some elite teams like Barcelona FC, ...
1
vote
0answers
43 views

questions on characterizing a variable into ordered, categorical or continuous

When building the regression models, some independent variables are of the following type x={1, 2, -100.1, 200.1, 300, 0, 0, 0, 0, 4000} If there exists an ...
0
votes
0answers
18 views

Summary of Probabilities

I am trying to summarize the ages of a population of five people. I have the following observations with an "Average" calculated at the end: ...
0
votes
0answers
42 views

Drop1() and Summary() on lm object

I need to analyse unbalanced data through linear regression: modJuin=lm(TleafMax~TairMax*orientation, na.action="na.exclude", data=aJuin) "TairMax" is a ...
0
votes
0answers
11 views

stat about variance of error

I have 2 population A and B: A contains the data with errors, while B contains the correct data. I want to find out a way to statistically correct the error of A. I compute the error from every row ...
1
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0answers
46 views

ranking based on lower confidence interval

I have a database of bridge scores from a local bridge club that effectively contains for this question, three fields: name, ...