A brief numerical description of a set of data.

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17 views

Need a name for a chart [on hold]

How can I call a chart with this approach: I have build a line chart to show the tickets opened, closed and backlog. I have it grouped by months. So in Jun/2015 I have 3 lines showing opened, ...
2
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0answers
15 views

How do I calculate a t-score from a p-value (gain scores and N also available)

I have this problem that only the gain scores with the p-value of a t-test are given in a scientific article. The authors neglected to report the t-test statistic and I'm stuck on figuring out how to ...
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1answer
26 views

Scientific P Value with adjusted R Square [duplicate]

I am running Spearman correlation between 2 variables weight and freight both being numeric. The output I have received from correlation is P value - 0.00E+000 and Rank R Squared is 0.61 and which ...
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0answers
36 views

How to combine time series measured in multiple experiments?

I have recorded neural activity over time in mice while they perform a task. There are several mice, each ran different numbers of sessions, and repeated the task different numbers of times each ...
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0answers
21 views

Regression Analysis and Conditional Expectation

I have to calculate a Expectation of some expression conditioned on something. I know alpha, Beta1 and Beta2 in the below expression. Income and Family_Size are 2 Uniform Random Variables between 0 ...
2
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1answer
64 views

Is it possible to compute a correlation between two variables from just means, standard deviations and sample sizes?

Is it possible to compute the correlation between two variables with just the mean, standard deviation, and sample size? If so, how would I go about it?
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31 views

Market Basket Analysis

I am learning "Market Basket Analysis" and I need a clarification about Advantages and Disadvantages or Pro's and Con's of the "Market Basket Analysis". And some cases where actually this "Market ...
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0answers
17 views

Measure for comparing serial measurements of multiple variables in treatment vs control group?

Can anyone suggest whether I am going about the statistics in an appropriate way? I have two groups of populations which have similar characteristics. In each member of both groups, serial ...
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0answers
13 views

minimum sample size to estimate chi square population mean

Let's say I have a chi square population, I required to evaluate the minimum sample size to estimate the mean with confidence level 1-alpha, I remember that Confidence level calculation based on ...
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0answers
18 views

Combining multiple metrics to provide comparisons/ranking of k objects [Question and Reference Request]

Collecting $n$ metrics about $k$ objects Suppose I collect $n$ metrics about $k$ objects. I am looking into valid ways to compare the $k$ objects so they can be "ranked". I think this may be ...
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1answer
11 views

Allocating consumption to products

Following scenario: Data from 12 truck companies is available. For each company the absolute value of diesel consumption is available. Each truck company can ship Product A, Product B and Product C – ...
2
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1answer
18 views

How to display potential outage when usage fluctuates greatly among customers?

I work for a Health Information Exchange. We have numerous "participants". Some send hundreds of messages a day, some might go a day or two without sending any messages. I'm creating a daily report ...
4
votes
1answer
82 views

Log Transformation

I am planning to run a 2x2x3 repeated measures ANOVA on reaction time data pre and post treatment. However, my data is skewed and I wanted to do a log transformation but have few questions. Can I ...
0
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1answer
24 views

Meaning of a higher out-of-sample $R^2$ but also a higher MSPE

I am comparing several forecasting methods using the out-of-sample $R^2$ and MSPE. Now I have encountered situations in which the $R^2$ of a certain method is higher than that of the other, but the ...
3
votes
1answer
87 views

What's the meaning of dimensionality and what is it for this data?

I'm doing my assignment for my "Modeling and Optimization" course, and now I have doubts on the first question: What is the dimensionality of the data? What are the min, median, max, mean, ...
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0answers
8 views

quantiles over moving window

A subrutine of a computer library calculates the quantiles over fixed spaces for all of my dataset : eg it calculates: ...
0
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1answer
31 views

Analysing data from summary table on R (interactions)

If I want to test whether data[,1]:setB is equal to 0 or not, do I just use the given t value and p value or do I need to add it with the data[,1] values? looking at the p value of data[,1]:setB, I ...
1
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1answer
34 views

Rewriting RegressionSS

I am having troubles in deriving the RHS of this formula: $$RSS= \hat{\beta}^{T}Z^{T}y-n\bar{y}^{2}$$ where $Z$ is the design matrix I am given ${y}^{T}y$ (what exactly does ${y}^{T}y$ stand for and ...
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1answer
49 views

How to rank monthly data, using both trends and averages

I have a very large data set containing the daily searches for some Wikipedia entries. I am using the number of searches as proxy of popularity and want to rank the entries. Lets say I have entities ...
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0answers
37 views

Quantifying how uniformly spread out points are?

I'm looking for a way to quantify how "clumped" vs homogeneously/uniformly distributed points are in a graph. Each collection has 100 points as (x,y) pairs. I've attached two graphs as an example. ...
0
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1answer
63 views

De-normalizing Google Trends data?

Does anybody have suggestions on how to de-normalize Google Trends data? The site says that their trends are made with the following metric: The numbers on the graph reflect how many searches ...
0
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0answers
12 views

Statistical Comparison of two different waves

I have two waves data for a couple of cities and I need a comparison W I W II City A 10,000 10,100 City B 200 202 City C 1500 1515 There is a 10% increase of ...
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0answers
29 views

Averaging standard deviations of unequal weight?

I'm sorry if the title is unclear, but I'm not sure of the appropriate way to phrase this question. I'm in med school (and sadly not as versed in statistics as I ought to be), and I am trying to use ...
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0answers
30 views

Descriptive and Inferential Statistics

I am doing a time series analysis (stock market returns) and I am currently looking at the summary stats. I know the definitions of the individual stats but the one I am stuck on is the relationship ...
3
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1answer
166 views

Using a rolling window in time series regression

I am learning about regression. I have done some cross sectional regressions which are fine. I recently did a simple time series regression. So I have a y & x vectors each containing 1000 ...
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58 views

Is there a name for this sort of plot? Is there any reason not to use it?

Suppose we have some time series data, with multiple samples per time unit. For example: ...
3
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1answer
97 views

How to compute the pdf analytically for the sum of generalized gamma

Question: problem statement $$z^d = \sum_i x_i^d $$ pdf of $X = \frac{d(\lambda x^d)^n}{x \Gamma(n)} \exp(-\lambda x^d)$ which is a generalized Gamma distribution and they represent euclidean ...
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3answers
64 views

interpret scatter plot if there is anything to interpret from it

I have an x variable and a y variables. I have done a simple scatter plot. I however don't really know how to interpret (if there is anything to interpret) the plot. I can't find any other similar ...
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58 views

MECE statistics

Consider a sample of a real quantity $X$. Say that we divide this sample into two mutually exclusive and collectively exhaustive (MECE) groups. Say we know the mean and median of these two groups, ...
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1answer
63 views

A Simple Regression Model for Our Experiment? [closed]

We know, In statistics, simple linear regression is the least squares estimator of a linear regression model with a single explanatory variable. In other words, simple linear regression fits a ...
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0answers
21 views

How to show ancillary statisitc of normal random sample?

Let $X_i \sim N(\mu,\sigma^2)$ and $X_i$ are independent. Then how to show that: $$ T = \left(\frac{X_1-\bar{X}}{S},\frac{X_2-\bar{X}}{S},\ldots,\frac{X_n-\bar{X}}{S}\right) $$ $T$ is an ancillary ...
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1answer
27 views

Suggestion on algorithm to visualize the safeness of an area [closed]

I am actually developing an app that notify users about "Safety Index" of the surrounding in a range of 1 Kilometer radius. I have did some research on how to calculating crime index which uses the ...
5
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0answers
155 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 ...
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2answers
30 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 ...
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1answer
97 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 .
9
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1answer
144 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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1answer
41 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 ...
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0answers
21 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
1
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0answers
21 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
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0answers
125 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
316 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 ...
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0answers
8 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 ...
5
votes
1answer
118 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 ...
6
votes
2answers
194 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
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1answer
22 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
104 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
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0answers
41 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
58 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
56 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
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0answers
440 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 ...