# Questions tagged [mean]

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

2,567 questions
Filter by
Sorted by
Tagged with
1 vote
10 views

### Is there a standard error of the mean for when population size is known?

Background Let us suppose that we are sampling from a finite population which is itself drawn from a univariate normal distribution. This accomplishes (1) having an underlying probability model and (2)...
• 3,383
19 views

### Estimate the mean vector and the covariance matrix using the simple returns

I would appreciate help with how to to estimate the mean vector and the covariance matrix using the simple returns in R. I have historical (weekly) values of five stocks from a capital market for a ...
20 views

### How can the sum of averages of my sample exceeds average of entire population? - market concentration

I want to see what percent of a market of listeners on a livestreaming platform my sample of top 100 musicians with the highest number of average listeners during a given month has. I only have ...
1 vote
9 views

I'm working on measuring the usage patterns of an app for a population of users. I want to find out if they usually log in at the same hours or if their usage times vary a lot. The variance of the ...
• 672
1 vote
10 views

### average of geometric and harmonic means

I have a stochastic simulation model in which three types of mean (arithmetic mean, geometric mean, and harmonic mean) are calculated for three different variables. I run the simulation 1000 times so ...
• 1,192
15 views

### Quantile Variance and Mean

As I read articles related to quantile measurements of moments, I only found quantile skewness and kurtosis definitions. However, I couldn't find any quantile estimation of variance or mean. Is it ...
13 views

### The distribution function of appropriately normalised trimmed mean $T_n(\hat{F}_n)$

A definiton of functional of trimmed mean: $$T^{\alpha}_n = (n-\lfloor \alpha n \rfloor)^{-1} \sum_{\lfloor\alpha n\rfloor + 1}^{n-\lfloor \alpha n \rfloor} X_{(i)}$$ A definition of the optimal ...
9 views

### Comparing measurements I got from my study with other ones from other studies

First of all I’m sorry if this sounds dumb! I’m really trying. I’m conducting a study on measuring adrenal glands in sick patients (3 measurements - cranial height, caudal height and length - in both ...
33 views

### How to know statistically for sure if respondents result on a likert scale is proofing anything..?

I have put a question what flow you get from a digital book, compared to paper from 7 (good) to 1 (bad). I only had 26 respondents, and this is the result: ...
208 views

16 views

### Comparing the width of two percentile intervals

Suppose I calculate 99% percentile intervals for two different sample sizes, for example N=10 and N=1000 by doing the following: I take 1000 samples of size N=10 from the population (not bootstrapping)...
• 331
16 views

### If we numerically code the categories of an ordinal variable, then can we determine its mean as in Likert scale?

Can anyone clear my doubts about 2 things. Doubt1)A dataset of Ordinal type having 2 modes, then does it mean that such dataset have 2 central locations ? Doubt2)As We know that we can not determine ...
22 views

### Variability and mean

I am working with future climate change scenarios and I end up with this question. Is it expected from a statistical perspective that a change in the mean goes hand-in-hand with a change in the ...
• 1
27 views

### How to sort individual tasks by duration when the only available data is the duration of two tasks together?

I have 2 sets of tasks, $S1$ and $S2$. A task can only belongs to one of the set (the intersection is empty). There is 21 differents tasks in $S1$, 57 in $S2$. A task from $S1$ is always followed by a ...
186 views

### Is it possible to find the 99th percentile using other percentiles?

I have the 10th, 20th, 25th, 30th, 40th, 50th (I assume this is the same as the mean), 60th, 70th, 75th, 80th and 90th percentile values of a data set. This is for the distribution of salaries in the ...
19 views

### finding central tendency

The following table presents frequency distribution of teachers of 1 year: Rank ----------Frequency Professor ------------7 Assoc Professor ------4 Asst Professor--------3 Instructor -----------5 ...
1 vote
30 views

### Is the mean posterior fit the same as the fit of the mean parameters?

Say we are fitting a parametric model $y(x, \theta)$ to some data (e.g. logistic regression). Given a prior distribution over the model parameters $\theta$ and observed data $x$, we arrive at a ...
• 461
37 views

### Conflict Between Confidence Interval and P-values - One Sample T-Tests

I'm conducting one-sample t-test using R. I calculated p value, effect size, and confidence interval, but they seem to be conflicting. Here is a sample code and output: ...
• 69
11 views

• 21
3k views

### Can mean be less than half of median if all numbers are non-negative?

I feel like I might be missing something dumb, but in a set of non-negative numbers, is it possible for the mean to be less than half of the median? Example: there are 999 numbers and we are told that ...
• 383
33 views

### Calculating average for each individual or not?

I have a question about how I should organize my data before doing some statistical analyses. In my data, I have a sample of rats for which the level of tear stains and body lesions is measured. They ...
• 81
7 views

### Descriptive statistical metrics of RMSE, MAE and R2 on cross-validation and holdout testing

I've tuned 100 models of each one LASSO (Least Absolute and Selector Operator) and Random Forest regression methods. I mean, to predict a hypothetical dependent variable, I've tuned 100 models for ...
118 views

### How does the 30% trimmed mean of this equal 6.167?

[6, 3, 7, 11, 5, 3, 8, 7, 2, 6, 9, 13, 10, 4, 3] So I'm going through some revision for stats, one of the questions asks to find the trimmed mean of the above data. I've worked it out but my answer ...
1 vote
32 views

### conditional quantile and conditional expectation

I was reading some papers and I found some parts are tricky to understand. Assume I have price data , what does it mean to calculate the conditional mean of the price data given yesterday price ? ...