Questions tagged [standard-deviation]
Standard deviation is the square root of the variance of a random variable, an estimator thereof, or a similar measure of the spread of a batch of data.
2,057 questions
5
votes
3
answers
514
views
How to estimate the standard deviation of a ratio?
I’m working with summary statistics (means, standard errors, and sample sizes) for two variables, and I’ve derived:
SD of variable A from its standard error and sample size
The ratio (P = A / B ) (e....
2
votes
0
answers
31
views
Use of total least squares to get standard deviation from fitted line [duplicate]
I am looking to fit experimental data to a line that predicts whether a circular pad will slip. This is done considering the shear force and the moment applied on the pad. I would also like to get a ...
- 21
0
votes
0
answers
34
views
Combining Mean and SD of different parts of bowel for same patient group
I am conducting a systematic review and Meta-analysis assessing the effect of certain medication on mucosal visibility during Endoscopy. I am looking to pool together the total visibility scores. ...
1
vote
0
answers
40
views
Sample standard deviation of a group of samples
I'm in introductory statistics. I have an idea of the answer here but I am unsure.
In this problem I have four random samples from a population of 60, each with a size of $n=10$. After calculating the ...
- 11
10
votes
1
answer
553
views
Does it make sense to average standard errors like this?
I have a collection of many experiments. In each experiment I do a simple linear regression where I get a regression parameter $\theta_i$ and I also compute the standard error of $\theta_i$ which I ...
- 103
3
votes
2
answers
200
views
Why doesn't the standard error depend on the number of samples taken?
I don't understand why the standard error of the mean does not depend on the number of samples of the mean that you take. To clarify, let's use a simplified version of the example in this answer. Two ...
0
votes
0
answers
29
views
are both sides of a bell curve equal in "intensity/quantity"?
I'm not sure if this is the right place to ask this, or if it makes any sense, but let's take a bell curve like modern IQ for example, with an SD of 15, and then let's take two points 70 & 130 ...
- 1
11
votes
5
answers
2k
views
"The standard deviation is the statistical measure that describes, on average, how far each data point is from the mean"?
I have seen this sentence or similar statments many times:
The standard deviation is the statistical measure that describes, on
average, how far each data point is from the mean.
But I thought the ...
- 261
1
vote
0
answers
75
views
Is there a way to simplify this online calculation of the adjusted Fisher-Pearson standardized moment coefficient
I am working with an accelerometer on a project where I am calculating the angles between the vertical line and the accelerometer and the horizontal line and the accelerometer (something similar as ...
- 143
2
votes
1
answer
78
views
How to Verify Reported SE or SD When Derived Correlation Is Invalid?
My current question is related to a previous post I made on the same topic. I am conducting a meta-analysis and have encountered several publications where, when I attempt to estimate the pre-post ...
- 251
2
votes
0
answers
77
views
Implementing standard deviation in js for a sci calculator: numerical stability concerns [closed]
i'm the guy who built this basic web-based scientific calculator over at scientific-calculator. it's all vanilla javascript using the built-in math library, so it does stuff like trig, logs, ...
- 46
6
votes
1
answer
382
views
How accurate are the standard error formulas to find the standard deviation of the sampling distribution of a statistic?
1. Definitions
The standard error of a statistic is an estimate of the standard deviation of the sampling distribution of that statistic.
The sampling probability distribution of a statistic is the ...
- 315
2
votes
0
answers
111
views
Sampling distribution for standard deviation with data following gamma distribution
For underlying data that follow a gamma distribution, what would be the distribution of the sample standard deviation across multiple samples? From what I have seen from data and simulations it looks ...
- 599
0
votes
0
answers
59
views
How to calculate SD for two groups [duplicate]
The first group has sample size 24 with mean=102.7
The second group has sample size 25 with mean 104.1
P value = 0.83
How to calculate SD for two groups.
Thanks for all.
2
votes
1
answer
94
views
Correlation between Pearson Coefficient of Time Series and Derivatives
I have two time-series signals, say θ₁[n] and θ₂[n], sampled at constant time intervals. To analyze their relationship, I compute the Pearson correlation coefficient over batches of N samples using ...
- 21