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

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1answer
24 views

Is this method of arriving at a statistic valid?

The following is an excerpt from an article about gender bias : Overall, 34 per cent of respondents readily admitted that their family preferred having more boys. Given the sensitive nature of ...
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0answers
13 views

Calculate mean of several tetrachoric correlation coefficients

how do I calculate the mean of several tetrachoric correlation coefficients? Do I have to use Fisher's z transformation before? Thank you
0
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0answers
24 views

Gaussian or Dirichlet Process from aggregated samples

For N individuals, I have the number of measurements taken per individual, the individual's mean measurement value, and the standard deviation of the individual's measurements, but I do not have ...
2
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2answers
57 views

Mean Preserving PDF Spreading

I have a histogram representing the PDF of an unknown discrete RV. The histogram is asymmetrical. To be clear, all I have is the histogram. Is there a known way to increase/decrease the variance of ...
1
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0answers
24 views

Mulitvariate normal truncated conditional expectation

There is three-variable multivariate normal distribution. Denote 3 variables with $X_1$, $X_2$, $X_3$. Let $\mu_i$ be means, and $\sigma_i^2$ variances of respective variables, and let $\Sigma$ be ...
0
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1answer
26 views

Find new mean from Normal probability

I have a problem as follows. Life of tyres normally distributed for a specific make. mean=24,000 km and sd= 2500 km. Question is: As a result of improvements in manufacture, the length of life is ...
1
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1answer
24 views

Compare means of group with a mean of a subgroup

It is possible to compare a variable, for example age, between an entire group of patients and a subgroup of patients (a part of the entire group)?
5
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2answers
112 views

Arithmetic or geometric mean to calculate an annual average price index?

I have monthly indices (Consumer Price Indices for 12 months) for a set of countries. I want to calculate the annual average for each country in order to have an average Consumer Price Index for a ...
1
vote
1answer
29 views

Comparison of two means within the same group

I created a pretest before my main study. The goal of the pretest is to find two brands that are equal in terms of liking and familiarity. I computed the variables in SPSS and I was wondering if I ...
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0answers
22 views

Should I use arithmetic or geometric mean here?

So I have monthly indices (Consumer Price Indices for 12 months) for a given country. I want to calculate the annual average for each country in order to have an average Consumer Price Index for a ...
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0answers
23 views

Suitable model for predicting mean output over time

I have 3 years of yearly historic data on the results of a harvest (of truffles) from multiple different areas involving multiple individuals harvesting in each area. The dataset contains: name of ...
2
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1answer
43 views

Can covariance be derived from means and variances?

In treatment studies it is common to report multiple outcome measures from the same subjects. The treatment effects on these outcomes are typically correlated so this should be taken into account ...
1
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0answers
14 views

Relationship between mean and variance not removed after data transformation?

I am a student and I am doing a research where I have a trait (lets say cow weight in kilograms) that presents a relationship between mean and variance. I also have a factor that is country/year ...
-2
votes
1answer
20 views

Is the mean smaller than the median

The mean and the median selling prices of single-family homes were reported to be \$163,900 and \$210,900. The report was not clear about which was which. \$163,900 is the mean and \$210,900 is the ...
4
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2answers
74 views

Finding the Mean and Variance from PDF

A random variable $n$ can be represented by its PDF $$p(n) = \frac{(\theta - 1) y^{\theta-1} n}{ (n^2 + y^2)^{(\theta+1)/2}}.$$ $\theta$ is a positive integer and $y$ is a positive parameter. If ...
0
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0answers
36 views

Bootstrapping with standard deviation, mean and autocorrelation

I found in the matlab examples a way to use mean and sd for bootstrapping: ...
1
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2answers
28 views

Will the mean of a set of means always be the same as the mean obtained from the entire set of raw data?

If I have calculated the mean for 4 data sets (which do have different sample sizes), can I then obtain an "overall mean" by calculating the "mean of the means"? If yes, will this "mean of the means" ...
3
votes
3answers
166 views

The probability of a random variable being larger than a sequence of random values

Suppose we have a fixed, known, $n$, and each $x_1 \ldots x_n$ is a random number generated uniformly over $[0,1]$. What is the probability that $x_n$ is the largest value in the sequence?
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0answers
17 views

Do I need to use weighted means with the Wilcoxon signed rank test?

I have 22 patients. They have been measured pre and post treatment. There are 3 measurements per patient before treatment (pre baseline), and four measurements after treatment (post baseline). There ...
3
votes
2answers
135 views

Are there any other distributions whose shapes can be determined by just the mean and the standard deviation?

For the normal distribution, With the mean, and the standard deviation, we know the shape of the specific normal distribution - that is, the center of it and how spread out it is. I wonder if there ...
2
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2answers
46 views

Standardize non-normal predictors before performing binomial GLMM using mean and sd?

I am planning to predict a binomial variable (1/0, a used point by an animal or point available to an animal in its range) using several continuous, distance-based predictor variables (distance to ...
2
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0answers
46 views

If $Var[X]$ is much larger than $E[X]^2$ is E[X] an unreliable estimate?

My question is simple and I got this confusion when going through a Markov chains text book.If $Var[X]$ is much larger than $E[X]^2$ is $E[X]$ an unreliable estimate?
2
votes
1answer
56 views

Is my sample homogeneous? [closed]

I have a sample of 110 values between 0 and 180. These represent total degrees in an arc, and I want to be able to figure out whether or not I have a widely variable sample of arc sizes or if I have a ...
0
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0answers
38 views

Understanding correlation between Multiple Intelligences (MI) and digital technology competency

I appreciate all the help I can get to help me understand. The research reported here is about whether there is a correlation between multiple intelligences (MI) and digital technology competencies. ...
1
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0answers
17 views

Finding mean value from lines of regression [closed]

The two lines of regression are $8x-10y+66=0$,$40x-18y-214=0$. Find the mean values of $X$ and $Y$.
2
votes
3answers
42 views

Mean test of log-normal distibutions

I have two data sets, which are assumed to be log-normally distributed. How can I test whether their means are statistically different from each other? I guess I cannot use the 2-sample t-test, ...
3
votes
2answers
95 views

How does one find the mean of a sum of dependent variables?

I know that the mean of the sum of independent variables is the sum of the means of each independent variable. Does this apply to dependent variables as well? Thanks.
0
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0answers
18 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
46 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
votes
1answer
19 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
votes
1answer
107 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
votes
1answer
36 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
vote
1answer
34 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
votes
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
votes
2answers
394 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
vote
0answers
12 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
40 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
vote
1answer
27 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 ...
5
votes
1answer
57 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: ...
0
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0answers
13 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
189 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
vote
0answers
23 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 ...
0
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0answers
48 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) ...
0
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0answers
16 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
16 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
799 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 ...