Average most often refers to the arithmetic mean, but more generally to measures of central tendency that use most, or all, of the data values. Examples include trimmed mean, Winsorized mean, harmonic mean and geometric mean.

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25 views

Which kind of mean (harmonic, geometric, arithmetic) is best suited for averaging probability ratios?

There are a bunch of examples around on how harmonic mean is more suitable for averaging rates, e.g. speed (when the distance is fixed). But what about probability ratios (p(A)/p(B), i.e. how much ...
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0answers
12 views

Comparison of average variances between groups of different size

I have 3 groups, split by highest degree of education. For each individual in a group, i calculate the variance of her income in a five year window. Let's for simplicity assume that i only do this ...
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1answer
15 views

When there are sub populations within a large population how is it treated?

say I sample 1000 people, 750 of them have a distribution similar to the result produced for all 1000, but 250 produce a distribution which fits entirely into the bottom quartile of the total 1000. ...
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2answers
37 views

Large data set, need PROPER way to calculate averages

I'm working on an excel sheet with 26k lines and need to calculate average costs per KG. I'm not sure which method of calculation to use as each is giving me different results. For example: ...
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0answers
8 views

Estimate average of a dataset when thresholded

Suppose I have a dataset $x_i$ (with $x_i >= 0$) of N samples. I would like to determine the average of the data when the data is limited to some theshold c: $limitedaverage(x,c) = \frac{1}{N} ...
5
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2answers
155 views

Average and standard deviation of timestamps (time wraps around at midnight)

I have lots of sensor data with timestamps like "2014-09-09 16:10:45" and accompanying sensor readings. To get some insight into these I want to find "unusual" events by looking at the average and ...
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0answers
12 views

Help with R and grouping/aggregate/*apply/data.table [migrated]

I'm very new to R and having trouble running functions to get the answers I need. I have example data PCSTest http://pastebin.com/z9Ti3nHB that looks something like this: ...
1
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1answer
38 views

cross tabulation of two variables with resulting average and SD

I am beginner of R software. I am looking for two variables and result cross tabulated but not in the form of frequencies. Could I get help on how to get result as average and standard deviation ...
12
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4answers
748 views

Good form to remove outliers?

I'm working on statistics for software builds. I have data for each build on pass/fail and elapsed time and we generate ~200 of these/week. The success rate is easy to aggregate, I can say that 45% ...
0
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1answer
25 views

Calculating Average Waiting Time

I am trying to calculate average wait time for one of the projects that I am working on. The way the project works is that there are pathways that students follow and each pathway has several steps. ...
0
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0answers
24 views

Average Growth Rate for Year 1 across 5 groups

I have a question that pertains to time series or more likely pertains just to simple math. Lets suppose that I am measuring the number of online visitors to 5 websites on a monthly basis, so I have ...
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0answers
18 views

web analytic: average session length based on visits numbers per minute

At hand, I only have the number of visits per minute for one web page (one day period), is it possible to generate the average session length of such page based on these numbers? Or and references I ...
1
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0answers
15 views

Local median and local average

I have two pictures representing two laboratory experiments. The idea is that every black band represent one sample. Now I need to use special application to measure the bands intensity, which tell me ...
1
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1answer
66 views

How to tell which recipe rating is better?

Comparing ratings for recipes I have often wondered is, say, 50 reviews of average 4.5 better than 31 reviews of average 4.8? Orbiting these considerations has been some idea of statistical ...
0
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0answers
71 views

Calculate the average of hourly data of three sensors

I am trying to calculate the average of hourly data of three sensors but the hourly timestamps of all three sensors are different. How is it possible to measure the average of hourly data of all three ...
2
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0answers
43 views

Averaging z scores when doing a “group by”

I have a dataset where each row is an hourly measurement of certain fields (columns). For each column I then add another column that is its respective z score relative to the entire population. If I ...
2
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0answers
33 views

How do I measure a speedup?

I have two versions of the same program. I apply a number of performance tests to both and measure their response time, for instance https://gist.github.com/valtih1978/d2cc2fe96fbbe1987ada ...
0
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1answer
11 views

Appropriate weighting for averages

What is the appropriate (or the advantages of disadvantages for each) measure for weighting mortality rates across countries: total population or total number of deaths? For example, if you have ...
0
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0answers
13 views

Web page scoring function based on readability (LIX)

I'm creating a scoring system for web pages based on their level of readability using LIX. A selection of pages from a web site are crawled and given a score. Besides average and median, what ...
2
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0answers
37 views

Average of percentile ranks

I have a number of objects (e.g. students) and their scores (possibly transformed into percentile ranks) across various events (e.g. tests). I would like to identify the students who consistently ...
1
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0answers
32 views

Is one-way ANOVA appropriate for comparing differences in (calendar) monthly means?

I have data for solute export by month (monthly mean values with year aggregated so that n=12), in one-way ANOVA the groups should be independent. A month of high solute export will probably lead to ...
4
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0answers
32 views

“Average” line over irregular log series data

I have simulation data from 1000 runs, plotting some measurable (in this case convergence of the algorithm) as a function of simulation time. Each run produces a discrete set of points ...
13
votes
6answers
880 views

How to detect polarized user opinions (high and low star ratings)

If I have a star rating system where users can express their preference for a product or item, how can I detect statistically if the votes are highly "divided". Meaning, even if the average is 3 out ...
0
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0answers
25 views

How to calculate the average selling period from inventory list (uneven intervals)?

Will I be able to calculate the average sales time (number of days) for an item, simply from the following 6 data points? Or will I need to repeatedly collect data, such that I for each day (say in ...
5
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0answers
81 views

Propensity Score Matching – How do the mechanics lead to a different result than unmatched?

The gist of propensity score matching, as I understand it, is as follows: You want to estimate the average treatment effect (ATE) of a treatment on some outcome. However, if you simply calculate the ...
0
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1answer
100 views

What is a tertile average of a group?

I came across a paper , where they have taken tertile average of a hormone level in a group. I am wondering what difference does calculating tertile average make? Thank You!
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0answers
39 views

Robust estimator of mean for skewed data

For heavy-tailed symmetric data, a trimmed mean or other robust estimator of the mean could be a better estimator of the mean than the sample mean. The trimmed mean will be biased for a skewed ...
3
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0answers
45 views

Combining apples and pears to form a single comparator

(I am not a statistician, so this might seem a dumb question, but I need your expert help!) I have data that looks like this: ...
3
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2answers
104 views

What effect does data averaging have on the variogram?

What effect does data averaging have on the variogram? To be specific, please see a simple example: ...
2
votes
1answer
54 views

Moving average for continuous functions

In statistics, the moving average is usually defined for discrete data sets. Is there a moving average concept for continuous randomly fast-oscillating functions? I am seeking for the moving average ...
0
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0answers
161 views

When is Micro-average Precision = Micro-average Recall

This page describes briefly on micro and macro precision used in computational evaluation: http://rushdishams.blogspot.de/2011/08/micro-and-macro-average-of-precision.html This paper surveys the ...
1
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0answers
64 views

Remove outliers and calculate average

I am trying to understand (by reverse engineer) the method a program is using to calculate an average value over a population. The program displays a (very very large) image consisting of tiles. Each ...
1
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1answer
44 views

Standard deviation of a sample when you know the average

I'm coding an app, a part of which is graphing values from a database. The graph plots the average value of every 10% of the values up to 100% so there are ten points along the x-axis. The graph ...
1
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0answers
36 views

Can mean values be seen as a form of PCA with a LOT of assumptions?

This question just occurred to me out of the blue. PCA is a way to reduce dimensions. Another way that is often (perhaps too often) used is to take mean values of two or more variables. This is done a ...
2
votes
4answers
120 views

Plotting averages when there are missing values

I have count data for a number of subjects in different groups I would like to compare. The averages of the cumulative sums are shown in the figure below. As you can see the Red group has a spike at ...
0
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1answer
40 views

Different group size average comparisons

I have 3800 stocks for which I calculate their return correlations. So I end up with a 3800 by 3800 matrix. Each stocks is related in some way to all the other 3799 stocks. For each stock, I create ...
2
votes
0answers
150 views

Comparing Averages of Pearson Correlation Coefficients for Significance

How can I test if two averages of Pearson's correlation coefficients are significantly different? For instance, I have data pertaining to participants' estimates of certain percentages (e.g. how many ...
2
votes
0answers
80 views

Calculating standard deviation after spatially and temporally averaging data

I have a spatio-temporal data set with (n,m) spatial and k temporal dimensions. My initial analysis consisted of spatially averaging the data and looking at the time dependent behavior. This resulted ...
0
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1answer
46 views

How to calculate average of a group when you know overall average, average of other group, and sample sizes per group?

I know the average of a group that consists of two subgroups. the number in the two subgroups the total the average of one of the subgroups. How can I work out the average of the other ...
0
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0answers
7 views

Determining the quality of low-pass filter estimate

I'm taking a low-pass filter, specifically an exponential moving average, of samples coming in every second. Those samples are of electric field strength, and suffer sizable noise. How can I ...
0
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0answers
21 views

Covariances between forecasts from different time-series models

I'm trying to compute the variance of an average of forecasts. But I'm not sure on how to get the covariances required to compute the variances. Here is the situation: Three ARMA(p,q) models for a ...
1
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0answers
45 views

Combining forecast from ARMA models

I have three ARMA(p,q) models for the variable X and using each model I produce forecasts for 12 months ahead. Note that in all three models the residual is normally distributed. Now if I want to ...
0
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0answers
13 views

Number of occurrences gives higher weights

I have this algorithm that I'm implementing that I need to change to give it a better accuracy. To give you an idea of the problem, I have a a bunch of lists that contain items and all items in these ...
1
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0answers
30 views

Sports winning percentage distribution

I am doing a study where I am measuring parity in sports. To do this I am looking at how well a year's winning percentages (WP) are distributed. I am currently comparing them to a binomial ...
0
votes
1answer
44 views

Variance of average of Bernoulli variables

What is the variance of the average of n Bernoulli distributed random variables Ber(p)? So Var(sum(xi)/N)
0
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0answers
11 views

What is the most appropriate way to combine three NTP server results?

I need to query an internet time server, in order to assess the staleness of streamed data I am receiving on another channel. I periodically make 3 successive queries, then use the combined error to ...
0
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1answer
33 views

How to fix weight in bayesan average

I am reading the article of wikipedia about bayesian average. This seems very interesting about on developing rating systems, but I have a doubt. How to fix the weight C of the average?
0
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2answers
82 views

Which measures of statistical dispersion should be used to estimate dispersion of slope of a trendline

Although I know how to calculate many of the statistical values, I have some difficulties understanding which one should I use in a specific situation. Here is my example: In my experiment I tried to ...
1
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1answer
123 views

Weighted average of measurements with unequal errors

Suppose I have the numbers below. Consider them as results of some measurement. ...
0
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0answers
13 views

Popularity and Difficulty score calculations within groups and sub groups

I have an examination application that carries questions of various difficult groups: a) Basic b) Standard c) Advanced Based on data generated by users taking these questions I am trying to create ...