The expected value of a random variable; or a location measure for a sample.

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15 views

Scaling data constrained to be varying between a floor and ceiling set of values

I have data that range continuously between the values of 0 and 2, usually somewhere in between close to 1 on average. 0 is a "floor" and 2 is a "ceiling." The data describe more than one group of ...
0
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0answers
41 views

Correcting data for mean but also variance

My data: I have data that range from 0 to 2 for numerous individuals. The scores are more or less normally distributed and vary continuously, but the scores are always between 0 at the minimum and 2 ...
4
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1answer
18 views

Different means with non-significant anova

I did an ANOVA test summary(aov(m$Y~m$type)) and I get a p-value of 0.067 i.e. the means are equal. But my means by type are these ...
9
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1answer
102 views

Show that if $X \sim Bin(n, p)$, then $E|X - np| \le \sqrt{npq}.$

Currently stuck on this, I know I should probably use the mean deviation of the binomial distribution but I can't figure it out.
2
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1answer
27 views

Quantitative Location Shifting Detection for Run-Sequence Plot

I am trying to complement a Run-Sequence Plot by some quantitative metric to validate that a dataset has a fixed location. Since the Run-Sequence Plot will be used in the early phases of Exploratory ...
1
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1answer
28 views

Quadratic mean convergence of a biased coin using conditional expectation

I'm a master's degree student and after a lot of research and some days trying I still can't get the answer for a question proposed by my Statistics professor. He asks to toss a coin with a random ...
3
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1answer
33 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 ...
3
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0answers
9 views

Test for participant subgroups in gradual means shift

In an experiment with 44 participants I have measured the response time for a set of stimuli, where the response could be a or b. The means of the two responses do not differ significantly (783.3 vs ...
3
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2answers
374 views

Difference between geometric and arithmetic mean

I still have problems to exactly understand the difference between geometric and arithmetic mean. I know that e.g. for returns, the arithmetic mean can be wrong (e.g. if I start with 100 $ and if my ...
1
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0answers
10 views

Constructing confidence intervals for mean of means, using standard errors [duplicate]

Is it possible to construct confidence intervals for a mean of weighted means using standard errors? I have 4 different weighted means ($p_t = \sum_{i=1}^{n} w_ip_i $ where $w_i$ is the respective ...
0
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0answers
29 views

The mean and standard deviation of an Kernel Density Estimation

[I have crossed posted this from StackOverflow. Not sure if this is allowed, but maybe there is a Python answer, or maybe there is a good stats answer] I have fitted a ...
1
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1answer
23 views

Significance of changes in mean values over time

I have 5 mean life satisfaction values for 5 different years; I have to find out if there is a significant relationship between the survey year and life satisfaction. How should I proceed? I was ...
4
votes
1answer
41 views

Is the mean of equal length subsets always equal to the mean of the set?

I've been fooling around with some numbers while learning R and would like to know if the following is generalizable. When I calculated the mean of numbers 1 through 100, I got this: ...
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0answers
9 views

Combining several variances, obtained from weighted mean and moving average

I have three questions 1: Can variances for different mean calculations be combined to obtain the combined variance? \begin{equation} S = \sqrt{s_1^2 +s_2^2 + s_3^2} \end{equation} 2: When using ...
3
votes
2answers
112 views

Unsure how to find the MLE for this model

The question I am trying to answer is confusing me as I don't know where to start to find a likelihood estimation The Question $y_i = μ + e_i $ where the $e_i$ are independent variables ...
-3
votes
1answer
65 views

Which mean value should I use

I am to test the transformational shifts in three different directions for 3 different imaging techniques in a group of 30 patients. I am trying to prove one is not statistically different to the gold ...
1
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0answers
21 views

Mean of an interval censored random variable

It is likely that I am incorrect terminology here, but I am trying to compute a "mean" of an interval censored random variable. Here is an example where: 1. a random sample from the standard normal ...
0
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0answers
20 views

Is 0 mean of residuals assumption crucial for every model?

I am writing a seminar paper about sales forecasting. I am doing couple of models and I am choosing which one gives the best forecasts (Decomposition method, SARIMA, Brown Exponential Smoothing, Holt ...
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0answers
46 views

How to name the concept of the mean shift divided by the standard deviation

In the context of a paper dealing with Statistical Quality Control, I am defining and using the concept of the mean shift divided by the standard deviation of a (normally distributed one-dimensional) ...
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0answers
13 views

Choosing between two parameters based on the mean and the standard deviation of the error

I am trying to interpolate data under the assumption that I have the true data. The interpolated data is dependent on a parameter which I am trying to estimate. For each possible value of this ...
0
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0answers
15 views

When to collapse data on subject level?

I have a question about when to collapse raw data to means per unit (e.g., subjects). In my data I have the following variables: id: subject id ...
6
votes
3answers
595 views

Can mean plus one standard deviation exceed maximum value?

I have mean 74.10 and standard deviation 33.44 for a sample that has minimum 0 and maximum 94.33. My professor asks me how can mean plus one standard deviation exceed the maximum. I showed her ...
0
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0answers
8 views

Weighted Standard Deviation [duplicate]

I got a problem calculating a weighted standard deviation for a municipality and its precipitation on various landcover types (LC). I got the mean values of precipitation for several days for each ...
0
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1answer
51 views

Confidence intervals vs P-values for two means

I know in studies where relative risk or odds ratio is calculated, if confidence interval overlaps 1, then the P-value is not significant. Is similar relation true for following situations as well? ...
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0answers
5 views

OOV “frequency”

I'm writing an algorithm to split twitter hashtags into their component words. I'm splitting the tags into all possible substrings, and then looking up each substring's frequency in a dictionary. I ...
0
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0answers
18 views

Compare two populations by their means… t-test?

I would like to have your opinion on the best way to compare two small sized populations of 13 and 14 individuals (but I have 3 tests for each individual on my dataset, so should I use 13 and 14 or 39 ...
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0answers
22 views

How to find normal quantiles?

A social psychologist interested in eating behavior wanted to divide students into four groups based on their eating proclivities. The four groups were those who were restrained eaters, moderately ...
0
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1answer
44 views

K means clustering of variable with multiple values

I have a sample data below that is from a large data set, where each participant is given multiple condition for scoring. ...
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0answers
38 views

calculate statistical value of the mean of a mean of a mean

EDITED FOR CLARITY Hello, Considering the picture below each values X could be identified by the indeces X_g_s_d_h ...
3
votes
1answer
30 views

Is the harmonic mean the maximum likelihood estimator for some common continous distribution's parameter?

If $y$ is a vector of continuous data the arithmetic mean is the maximum likelihood estimator for $\mu$ when assuming $y \sim \text{Normal}(\mu,\sigma)$ (not uniquely, of course). The geometric mean ...
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0answers
24 views

What kind of process is this?

For a k-steps stochastic process, assuming that it takes tk mins from the first step to reach the kth step. If we statistic the mean of cost time (tij) from ith step to jth step and the cost time ...
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0answers
36 views

What is the mean and variance of this probability distribution?

I don't know if this distribution has a name or not so the best I can do is describe how it is obtained. You start with two arrays of n uniform random variables U(0,1) where n>2. I will provide a ...
0
votes
1answer
24 views

Can I take the mean of an indirect measurement?

I've been told that one shouldn't take the mean of indirect variables. Specially, I should not give the standard error as the error of the mean. To give an example, if I'm using Ohm's law $V=RI$ and ...
0
votes
1answer
17 views

If I have estimated set of values, how to get the mean?

I am a beginner in stats and need to get this clear please. I have estimated set of values and need to calculate the mean. Do I still need to divide over N or the sum of all estimated values will be ...
0
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1answer
36 views

The difference between the standard error of the sample and the standard error of the mean value

I have an assignment that gives 48 counts of the same phenomena occurring over the same time interval. I am asked to a) Calculate the mean of the counts b) Calculate the standard error of the sample ...
2
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0answers
38 views

Mean and variance of Cox process

Consider the (doubly-stochastic) Poisson point process with rate $ \lambda(t) = \rho e^{-t/\tau} $ where $\rho\sim\Gamma(\alpha,\beta)$ is a Gamma-distributed random variable. I require the mean ...
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0answers
60 views

What are the pros and cons of using median imputation to handle missing value?

I have to choose between median or mean imputation to handle missing values. I feel median imputation will work better because it is a number that is already present in the data set and is less ...
3
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0answers
42 views

Sum of Bernoulli random variables

I need some help with a homework assignment. The question I'm given is: "Suppose that $X_1, X_2,..., X_n, W$ are independent random variables such that $X_i\sim Bin(1,0.4)$ and $P(W=i)=1/n$ for $i=1, ...
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0answers
12 views

How do I determine sample size to validate a requirement when I have a lot of margin?

I apologize if a similar question has been asked, but my search has yielded no results. I am having some trouble nailing down the correct methodology to use to design an experiment I am working on. ...
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1answer
41 views

HELP: How to compute a mean for specific cases, NOT the entire dataset! [closed]

I am trying to compute a mean of several variables for just two cases, rather than compute the mean of several variables and include all the cases in the dataset. How does one do this? Thank you for ...
1
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1answer
25 views

Calculating the mean excess loss

Suppose $X$ has the following pdf: $$ f_x(x)=0.01 \qquad for\space 0\le x<100$$ Find the pdf of $X_p$ (the excess-loss variable) and calculate the mean excess loss for $d=10$. \begin{align} ...
2
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2answers
61 views

The Mean of the number of times until an event occurs

Lets say we have 6 cards in a hat, that are all red. Now each time, we blindly take a card out of the hat: - If the card is red, we take it out of the hat and insert a blue card. - If the card is ...
0
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0answers
18 views

How to test adjusted mean in R?

I have got eight adjusted means for eight subgroups in a survey study, but I don't know how to test the differences of these eight adjusted means. Any suggestion is appreciated. Thanks!
8
votes
1answer
233 views

Can we use leave one out mean and standard deviation to reveal the outliers?

Suppose I have normally distributed data. For each element of the data I want to check how many SDs it is away from the mean. There might be an outlier in the data (likely only one, but might be also ...
2
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1answer
217 views

Why does a confidence interval including 0 mean the difference is not significant?

Could someone please explain why zero being inside or outside the confidence interval tells you whether or not the difference is significant?
2
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0answers
20 views

with two EWMA means of different window sizes, can we estimate any other means? slopes? jumps?

EWMA is defined as follows(1, 2, 3, 4, 5): $$ \mu_{N} = \frac {1}{N} \Sigma_{i=1}^{N}x_i $$ $$ =\frac {1}{N} \Sigma_{i=1}^{N-1}x_i + \frac{1}{N}x_{N} $$ $$ =\frac {N-1}{N} \frac{1}{N-1} ...
1
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1answer
28 views

Sequence of Random Variables

I am confused about how to approach sequence of random variables that are not identically distributed. For example, consider a sequence $X_1, X_2, \dots, X_n$ with the pdf: $$ f(X_n)= \begin{cases} ...
0
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0answers
52 views

What is the multivariate analog of the median?

There is a univariate mean: sum the points and divide by the count. There is a multivariate mean analog - the centroid, a point in a multidimensional space. (1). For the median one sorts the list ...
4
votes
1answer
179 views

Can the mean lie outside the the interquartile range (Q1 and Q3)? and if so what does it do to the distribution

Can the mean lie outside of the interquartile range? I realize that extreme outliers can affect or pull the mean, but can it pull the mean outside of the interval from the first quartile to the third ...