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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1answer
44 views
Confusion regarding weighted average
This is a pretty simple question and I'm wondering how to go about finding a solution. I have the following data.
...
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0answers
49 views
Mean and variance of call center data
I have a fairly involved homework question, I was wondering if I could get some help.
There are two types of phone calls arriving at a switch, long-duration and short-duration. Each day the number ...
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0answers
28 views
Variance of average of estimate computed by importance sampling
I have a random variable X of which I sample N values [$x_{1}$...$x_{N}$]. From these values I calculate the estimate P of function H(x) using Importance Sampling, i.e. $P = \sum_{i=1}^{N} ...
1
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0answers
45 views
Taking average of linear regression results
Say I have a very large sample of observations, like a thousand of them, and I want to do (multiple) linear regression on them, i.e., regressing the response variable on the predictors. Now instead of ...
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1answer
18 views
Average in complexity
Lets say that complexity if individual is ranked in ordinal scale as :
1 = simple 2= moderate 3= complex 4 = very complex, how would i indicate the average of complexity by taking from 100 ...
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1answer
43 views
Getting the number of active employees per month
In large companies with thousands of employees, how to get the number of employees per month? everyday there could be new employees, resigned or terminated employees, etc. If I want to get the number ...
1
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0answers
32 views
Data set of means
Suppose we have a data set of means and standard deviations. So the data are of the form $X_1=(\bar{x}_1, \bar{x}_2,\dots, \bar{x}_n)$ and $X_2 =(s_1,s_2, \dots, s_n)$. Is there any utility in looking ...
2
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1answer
32 views
How would you calculate average time to make a breath?
Suppose I wanted to know a one minute average of the time it takes to make a breath. So basically I would record the number of times I made a breath during one minute (one inhale and one exhale) and ...
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1answer
121 views
Stata “Regress” Command and Finding Average Difference [duplicate]
I want to determine the average difference between 1998 treatment schools (group1=1) and comparison schools (group1=0) in the following two characteristics:Proportion of female ...
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1answer
41 views
Stata Help needed with “regress” command and average difference [closed]
I have to determine the average difference between a treatment group, group1 and a comparison group, group 2 when looking at 2 characteristics, Proportion of female children (“female”) and Average ...
1
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1answer
47 views
Average rate versus average period
I am working on a project where I need to do workload balancing, and to see how well my approach is working I want to compute both the average amount of time between requests for a workload and the ...
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1answer
34 views
Average variation points
Having a score board
Points
Day 1 1000
Day 2 1050
Day 3 1010
Day 4 1010
Day 5 1030
How to calculate the average variation points? i.e. How many ...
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0answers
8 views
Can significance be determined from data on individual companies in different industries?
I have gross margin data from 20 different industries (each industry has 20 to 60 companies). Within each industry, at least one company used a new production system (about 30 companies use the new ...
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2answers
107 views
Always get confused by “probabilities and weighted probabilities” type of questions as cant differentiate between two
Urn 1 contains 5 white balls and 7 black balls. Urn 2 contains 3 whites and 12 black. A fair coin is flipped; if it is Heads, a ball is drawn from Urn 1, and if it is Tails, a ball is drawn from Urn ...
1
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1answer
76 views
Study design involving 4 variables measured every month for 5 years
I want to design a study on hemodialysis patients. I know from basic science knowledge that there are four variables (suppose a, b, c, d) which effect the rates of heart attacks/ strokes and ...
2
votes
0answers
36 views
How to improve estimation of a deconvolved density
I have the following problem:
Y = X + e
with
Y = Total reaction time (noisy signal)
X = selection time (signal)
e = discrimination time (noise)
I am interestend in the distribution for X and ...
1
vote
1answer
57 views
Estimating conditional mean
Suppose I have a uniform random variable $X$ taking values $\{1,...,n\}$, and two functions $v(X)$ and $w(X)$.
I know that $v(X)$ and $w(X)$ are jointly distributed with correlation $\rho$.
(And can ...
4
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0answers
20 views
Average of ongoing durations
Suppose I run a community center and I want to find the average length of time that someone is a rec center member. It is straightforward to do this with people who have already cancelled their ...
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3answers
86 views
How to prove that averaging averages of different partitions of a dataset produces the same overall average
After testing some cases, it appears to be true that if you create partitions in a dataset, average the data in the partitions, then average the averages, you get the same result as if you averaged ...
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3answers
456 views
What are the different types of averages?
I know there are three types of averaging methods in statistics: Mean, Mode and Median. Are there any other type of averaging methods that statisticians use?
How do I know which method is best ...
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1answer
54 views
Average of rate of change in a set of independent change events
What is the right method for computing average of percentage values? Arithmetic average, geometric average, or something else?
Here's an example of problems I'm talking about. Suppose for years 2009, ...
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1answer
30 views
Notation of a resampled mean
For a work that I have to document, at some point I do N resampling of the initial sample and generate N means out of them (some kind of bootstrapping). Pretty easy, however I don't know how to write ...
3
votes
1answer
49 views
Formal way of defining a weighted average
I am looking for a nice and formal way to define moving averages :
$y = \sum_{i=0}^N w_ix_i=<\mathbf{w},\mathbf{x}>$
and especially the fact that weights have to equal one, i.e.
...
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1answer
37 views
Sampling Distribution [closed]
Suppose $X \sim N(\mu, \sigma^2)$. After $n$ independent draws $\bar{X} \sim N(\mu, \frac{\sigma^{2}}{n})$. I am assuming that each draw contains $n$ numbers? Because if each draw only had one number ...
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2answers
57 views
Interpreting regression results for aggregate data: does it make sense to refer to the “average of average”?
I don't have access to individual data, so I have to rely on aggregate data for a large number of cities in a country.
If my outcome variable is the log of city average earnings and the predictors ...
2
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1answer
208 views
Harmonic mean with zero value
How does harmonic mean handle zero values? what would the harmonic mean of {3, 4, 5, 0} be since $1/0=\infty$?
8
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4answers
867 views
What is the distribution of an average of Poisson random variables?
If I have random variables $X_1,X_2,\ldots,X_n$ that are Poisson distributed with parameters $\lambda_1, \lambda_2,\ldots, \lambda_n$, what is the distribution of $Y=\left\lfloor\frac{\sum_{i=1}^n ...
3
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0answers
45 views
Statistical properties of a 3D field from spatial averages at different scales
I'm trying to estimate the statistical properties of a 3D vector field (the magnetic field vector in the solar atmosphere) over a 2D field of view from observations. I will neglect for the moment that ...
2
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0answers
97 views
Combining correlated measurements - negative weights
I'm trying to get the analysis of this (I hope) simple case correct in my head.
Lets say I measure the same thing two different ways, on the same set of data. Call these measurements $y_1$ and $y_2$. ...
3
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0answers
32 views
How to find 1-year population average with intermittent series data
I have performance review data and scores (ranging from 1 to 4) for employees of a company. I need to show the company average over the past year. However, the employees were only ever reviewed for a ...
0
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0answers
38 views
Count average on data for a long time period
I have a program system, where present a lot of tasks. Each task need some time for an execution and monitoring system writes time of execution for each task to a database.
I need to calculate average ...
2
votes
1answer
177 views
Moving average signal confidence
Please advise how best to approach the following;
I have a trend following trading signal comprising a trailing simple moving average over n data points. The data is stationary. Currently i ...
1
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1answer
191 views
Using averages of two different size groups
I'm not really "into" statistics, so I could use a hand on this one. I have two small groups, one has 12 students and the another one has 6.
Both groups answered a questionnaire and I'm trying to ...
4
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2answers
122 views
Incorrect reasoning in obtaining average family income
This is a relatively easy question but I am new to statistics so I hope I could get a better idea. Me and my friend were discussing the following:
My friend said that if someone wants to find the ...
2
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1answer
751 views
How to perform a t-test to compare treatment and control groups when the experiment has been replicated three times?
I have data from a experiment that has been repeated 3 times under the same condition. Each time, 5 measurements of each of 2 groups (a control and a treatment) were taken. I want to run a t-test on ...
4
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1answer
274 views
Negative weights in a moving average?
A number of well known moving averages, such as Spencer's 15 point MA, and Henderson moving averages have negative weights in the averages.
What does this mean in a conceptual sense? What information ...
3
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2answers
291 views
How to adjust average rating for sample size on rating systems with more than two categories?
After reading How Not To Sort By Average Rating which deals with confidence interval for a Bernoulli parameter how would you extend it to more than two levels?
For example: Items are scored between 1 ...
5
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2answers
224 views
Combining experimental error in a mean
This is a real noob question but when I try to google it, I quickly run into a terminology forest around standard error of the mean and mean percentage error and all kinds of terms involving 'mean' ...
3
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2answers
584 views
Is there a reliable recursive formula for a simple moving average (moving mean)?
I've tried some recursive moving average formulae (to reuse a previous output instead of summing the whole n-long set for every ...
3
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2answers
95 views
Averaging images
I want to see if it is possible to analyse openly available images (from google, flickr, etc.), and conclude something from them (the same way one might do this from census data but with images as ...
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0answers
81 views
Estimating 2D mean from uneven samples
This CrossValidated post on estimating mean from uneven samples suggests using a (any) Riemann Sum to estimate the integral of an unevenly sampled 1D function.
To me the obvious extension to 2D is ...
1
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1answer
75 views
Average value from ranges in a survey
I have a questionnaire where some of the questions concern ranges, the answer alternatives are:
0
1 - 15
16 - 30
31 - 45
46 - 60
60+
(the numbers are minutes per week, not that it matters)
If I ...
3
votes
2answers
2k views
Calculate average of a set numbers with reported standard errors
I have 365 daily measurements that all have standard errors associated with them.
...
4
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0answers
103 views
How to average Spearman correlations? [duplicate]
Possible Duplicate:
Averaging correlation values
I have a number of users, and for each user I have 2 ordered lists of items (one is from observation, one is generated by an algorithm). ...
2
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0answers
161 views
How to explain certain patterns appearing after kernel averaging?
Having a 2D map filled uniformly by random values (Figure:top-left), the next maps are kernel averaged with a kernel of sizes ...
1
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1answer
770 views
How do you find the average in this Poisson Distribution problem?
Suppose that the number of accidents occurring at a particular intersection each week is a Poisson random variable. It is estimated that the probability of having at least one accident in a week, at ...
1
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2answers
216 views
Does “x per y” always refer to the arithmetic mean?
I recognize that there are many types of averages. That said, does "x per y" (e.g. visits per day) always refer specifically to the arithmetic mean?
For some context, I saw this recently where ...
2
votes
1answer
86 views
Average number of cards of a particular suit in a hand
I am creating a card game AI for an iPhone game and I'm stumped trying to come up with this statistic.
The deck has 4 suits. The cards are numbered 1-14 in each suit and there is one Joker. So, the ...
1
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1answer
82 views
How should I characterize the “typical” variance of a large collection of variables?
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 ...
4
votes
3answers
410 views
Chi-square test for checking if values are close to zero?
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 ...
