variability

I would like to calculate intrabatch variability of parameter A, which is normally distributed. I have data of 50 batches (the same process), for each batch I have one representative sample with sample size = 10. I have calculated pooled SD from the samples of all 50 batches (I assume this is...

Hi, I would like to estimate to what degree (e.g. 20% fixed) the costs of e.g. a central function like HR develop with the growth of e.g. Revenue within a company. My first though would be a regression for estimating HR costs Y if sales (X) go up by $1. However I'm supposed to classify HR costs...

I'm Currently working on Gait data,collected from 3-axis accelerometer(large data set).Need to compare(Left leg acceleration and Right leg acceleration data) and should find Symmetry and Variability Quantitatively by looking at the distribution of the acceleration data,have already found...

My doubt is the following 'it's possible to compare means of two independent groups without considering standard deviations" ? For example: Control Group: mean +- standard deviation 50 +- 10 mm Experimental Group: mean +- standard deviation 100 +- 30 mm I am very...

Hello, We want to identify for which categories we need to differentiate in assortment over stores. We want to prioritize categories from highest potential to lowest (since we deal with 200 categories we can not do all categories at once). One of the things we want to take into account is...

Hi, I need statistical test which would tell me which percent of variability in dependent variable is from given independent set of variables and which of unknown ones. Example: Model: Y = Model (X1, X2, X3, ....) Measurements of Y, X1 and X2 are given. I need test which tells me the portion...

To compare several independently distributed time series, I decided to take a compare their coefficient of variations. Is there any better way to compare them and even group them?

Hi: I am wondering if I can ask a bit of help. I have patients undergoing two different procedures (binary factor). One of the outcomes is is a continuous variable (range from 0 to 2, but heavily skewed to the right). I am only interested comparing the variability between the two groups...

I have been looking for a solution to this problem for days, so I hope you can help me. I have several datasets containing hundreds of variables, measured at the same time point and with the same method. Some of these variables have been measured more often and assume consistent values. Some...

Novice STATA user here... I ran a meta-regression to analyze how prevalence rates of personality disorders vary according to differences in study design (e.g., gender of participants m/f). In order to see if there is enough variability within each of my dependent variables (10 different...

Hello, I'm trying to compare a real dataset with a random (synthetic) distribution to determine whether a pattern I see in the data is real or the result of a random distribution or poor sampling. I've been struggling with this problem for weeks and no number of websites or books are...

I don't understand the Trial of the Pyx example in the following (http://press.princeton.edu/chapters/s8863.pdf). De Moivre's Equation (http://math.stackexchange.com/questions/253486/name-of-de-moivres-equation) Excerpt: In 1150, a century after the Battle of Hastings, it was...

Hello everyone. I'm doing research on small distance variability between exploration wells. I have all databases, f.e. gamma-ray in every 10 cm depth. What I need to do is to find correlation between two wells. So, my question is which methods should I use? I'm thinking aboout T-test, but...

Dear all, I have a twofold question. 1) I'm doubting on how I calculated my between subject variability for a pre/post test design. What I did is dividing my subject mean square (MSb) by the grand mean. Is that correct? 2) I have normalized the data (for each subject, always same way fro...

I have the need to take a variable that is normally distributed around 0 and the lower and upper bound is at -1 and 1. I need a transformation to flatten the top and widen the tails. I just happened to think this may be a fishers z I'm looking for. If so I'll mark this thread as solved.

Dear experts and users: I was instructed to calculate the within-subject and between subject variability of a data set from one of my PIs. I would love any guidance on how to report them! I have scoured Google and textbooks, but unfortunately there is a scarcity of guidance. Would a...

Hi I am having trouble understanding census populations, variability in census populations, and how and why one is allowed to attribute significance to tests conducted on data derived from census populations vs population samples. 1) Is there any point at which missing data points invalidate...

I'm struggling to find the appropriate solution to a project that I'm working on. I am trying measure the variability of lead time on products that we purchase I can't figure out what an appropriate calculation would be. Below are some of the details. - I'm trying to compare vendors. Some...