Questions tagged [minitab]
Commercial statistical package distributed by Minitab Inc.
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How Minitab calculate optimize number of bins of a normal distribution histogram
I used minitab to draw a normal distribution histogram and saw that the number of bins in that graph doesn't follow any rules to calculate bin size that I know of (sturge, square-root, rice, freedman-...
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Interpreting the results of RSM Analyses from Minitab
I am working on a small project to optimize the performance of an iron electrocoagulation reactor for water treatment.
My professor wanted me to build a model to predict turbidity removal based on ...
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58
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DoE: Why so many center points for Response Surface design in Minitab?
I'm finding what seems like an absurd number of default center points with the following Response Surface DoE setup in Minitab. Can someone please help me understand why they're needed and if I can ...
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Equipment reliability in medical device manufacturing setting
I am working in a medical device company and there is something that I would like to test out on the manufacturing line. I am not a statistics expert so this is something that is out of my skillset.
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Sample size effectiveness
I work in manufacturing and must report to my boss how effective our sampling is. Can someone please point me in the right direction?
This is an attribute specification of porosity in a casted part. ...
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Why does Anderson-Darling statistic increase as Frequency is increased for my data?
I have been carrying out sieve analysis to estimate the median particle size of a powder. I wanted to check if the data so far followed a normal or lognormal distribution, as I have come across ...
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141
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Confidence interval for variables with multiple categories - estimation of difference
I have performed a chi-squared test on two categorical variables - one is a dichotomous variable (eg survived, died), whereas the other has multiple sub-categories (location A, location B, location C ...
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How should i treat this data, as a covariate or as a factor?
In my research group, I'm in charge of the statistical analysis of the data generated by the team, but I am fairly new to all of these statistics. So, I have this ambient temperature data (which on ...
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Explain the correlation between 7 critical success factors and 8 factors representing firms characteristics with ANOVA
For my dissertation I need to check if how 7 factors vary is somehow explained by how 24 other factors vary. (how the critical success factors (which are 7) vary is explained by the characteristics of ...
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Stats on categorical variables
For a little background, I have 2 groups in my analysis. I have coded some lab results as 1 = bacterial colonies are red 2 = bacterial colonies are dark and shiny and 3 = bacterial colonies are black ...
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170
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Lower confidence with larger sample size? Tolerance interval for distribution-free data
I am trying to find the sample size required in order to establish a tolerance interval which contain 99% of the population, with 95% confidence. The results from Minitab for a sample size of 473 are ...
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Making sense of an actual equation obtained after Box-Cox transformation
I have recently performed and analysed an experiment and I am currently stuck on making sense of the outcome. Any help would be much appreciated.
The experiment consists of a simple DC voltage source ...
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Can I change the constant in the response surface regression?
I analyzed my data using response surface regression using Minitab. the constant is the model is very close to one of the material properties (strength). I would like to keep the constant at a certain ...
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181
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Mixed effects/nested model giving different EMS tables in R and Minitab, and I believe Minitab is incorrect. Anyone know why it would be wrong?
I have a dataset at https://docs.google.com/spreadsheets/d/1PB_S7oX2Tqgz_BEUUcHfLOww0cNJ-IgN6B34UTequlw/edit?usp=sharing that shows a mixed model where Machine and Station are fixed effects and Power ...
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Why is error contribution higher than factor contribution in ANOVA?
I used Taguchi L9 orthogonal array design for my experiment to optimise the tool geometry parameters for better surface roughness. I have conducted experiments as per DOE and I used Minitab to find ...
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Most suitable stat test for this data?
Looking for a difference between: count and size, exposure, animal and colour (CountXsizeXexposureXanimalXcolour).
There are 480 data in each column of which:
240 each - size (0.5mm and 2mm)
240 ...
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Normality test for discrete values of a continuous variable
I have a dataset with several hundred pH measurements from a factory line. This dataset will be used to infer process capability using Minitab.
On a physical basis, pH is a continuous scale (being ...
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I want to compare a forecast with actual inventory, what statistical tests can I use?
I have two datasets, both are .csv files:
Forecast- Marketing team's forecast of inventory levels that would be required in 2019
Inventory - Factory's records of actual inventory values recorded in ...
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467
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Determining probability from categorical variable data
Whist reviewing some test data I am looking for advice on identifying the correct statistical tool(s) to help me answer two questions. The data I am looking at is from a cytotoxicity test, whereby a ...
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303
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Different PLS model when using plsr() function in R or Minitab PLS regression menu
I have a PLS model made in R with plsr() function (from package pls); I have chosen the right number of components with cross ...
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Independent Variables in Multiple Regression found Significant, but Insignificant when ran Individually
I've ran into (by accident) something that has stopped me in my tracks. When running this analysis:
I get that Use, FA, and Detections are significant predictors for fixation duration on map duration....
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Split plot design with psudo replicates
I am working on a project and need to analyze data that I know is an example of a split plot design but I am having trouble setting the model up correctly.
Here's the situation:
A bakery is testing ...
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1
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Understanding formula for Short Term / Long Term Degrees of freedom in minitab
Now I'm new to statistics, but the last time I did degrees of freedom, the formula I used was
$df = n-1,$
but I've just been playing with Minitab and reading the help to files, and I noticed it is ...
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One tailed paired t-test
Ok, this might be an obvious question but it's had me stumped.
Let's say we're doing a test to see the improvement on test scores before and after some process.
We could state the hypothesis as:
H0:...
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208
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Testing beta is 1 with Minitab or SPSS [duplicate]
I would like to run a regression to test a hypothesis that alpha = 0 and Beta = 1. I understand minitab or SPSS regression will test whether alpha or beta is 0.
How do I test whether beta is equal ...
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287
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ARIMA R vs Minitab [closed]
A simple question: Is the algorithm for calculating the fits using the Arima function of the forecast package of R different ...
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1
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548
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What is the number of iterations used to estimate the ARMA coefficient
If we are using the LSE "least square error" equation for getting the AR and MA terms:
by getting the LSE in function of the coefficients and differencing it then equating it to zero.This yields ...
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extreme right skewed data, bootstrap or mann-whitney?
I am an old dog (DB guy) trying to learn new tricks (stats) and was hoping someone here could tell me if this is a good approach:
I have to analyse extremely right skewed counts of events over a ...
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Do general linear models actually fit a linear function to the data?
If I understand correctly, linear regression involves fitting a linear function to a dataset and computing the error in that function. There's also a notion of "general linear model" which seems to be ...
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Why these the results in factorial 2k experiment analysis with R are different of the Minitab?
I'm studying DoE $2^{k-p}$ and I'm attempting to replicate an experiment using R software from a article that was run in Minitab, but the results are different.
Regression model presented in the ...
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Identify the underlying distribution from multiple samples
I have $30$ unequal samples ($n_i >1000$) from a supposedly same population. How should I go about identifying the underlying distribution of the population using these $30$ samples simultaneously?
...
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A proper function for nonlinear regression with 3 predictors
There are three independent variables in my experimental work, namely flow rate (0.5 ≤ Q ≤ 9 where ΔQ = 0.5), particle size (a = {6, 10, 15}), and a geometric parameter (AR = {AR1, AR2, AR3, AR4}). ...
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Statistical analysis of bud burst - handling a whole group of 0s with a mean of 0?
I have two treatments A and B which have been applied to tree buds to see if they will burst in a set time period. The outcome is binary - burst or not burst (yes or no, 1 or 0). There are an uneven ...
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regression equation of factorial design [closed]
I was wondering why I get a different kind of regression equation when I do the same data in a different way(create DOE in the minitab vs type the data myself ).
For example, when I do the job as the ...
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Check for equal slopes with Chi-Squared test
I have the following distribution of counts where blue represents blue shoes, red represents red shoes and green represents green shoes. Though the total sales numbers differ I want to check if the ...
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230
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Choosing alternate hypothesis in two sample t-test
I am trying to do two-sample T-test in Minitab where I have to compare average of one variable with another binary variable. I am having difficulty in choosing alternate hypothesis. So just for ...
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How do I assign a probability distribution to all combinations (4500+) of a single variable?
I'm trying to simulate the delivery times for a fast food restaurant (i.e. the time it takes the delivery guy to reach the client from the restaurant).
The locations of all clients are put in ...
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Design of Experiments on Minitab output [closed]
I am trying to create a factorial design using Minitab. I have 2^4=16 runs, I would like to divide these up into 4 blocks, to spread the experiment across 4 days. I will have 4 judges to complete ...
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692
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Confidence interval for Mann-Whitney test (Hodges–Lehmann estimator)
Does anybody knows how to calculate the confidence interval using normal approximation for the Hodges-Lehmann estimator (median of Y-X)?
This is how Minitab performs calculation, but I cannot find ...
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Time series-Minitab-fixing Autocorrelation problem using first difference
I am studying time series. I have the following data:
The Model for this Data is given by:
$Revenue= \beta_0+\beta_1{X_{1t}}+\beta_2({X_{S1,t}})+\beta_3({X_{S2,t}}) + \beta_4({X_{S3,t1t}})$
or ...
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How do I compare the co-efficients of two binary logistic regression models?
I have data on Liver Disease Patients, with the response variable being whether the patient has liver disease or not(1 or 0) and 7 predictor variables, such as age, gender, protein levels etc.
Now, ...
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How to calculate standard error of means in minitab
I am going through the 2 way anova steps provided by minitab. But I just can't get the answer for SE Mean as shown in this website (http://support.minitab.com/en-us/minitab-express/1/help-and-how-to/...
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Fourier Transform-Time stamped data and Linear Regression
I am new to DFT (Discrete Fourier Transform), but I am trying to use it to decompose my traffic volume data into two vectors (x,y i.e. independent and dependent variables). Afterwards I can apply a ...
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GLM in R and Minitab gives very different results when interaction included
I run a GLM in what I believe is the same way in Minitab and R. With no interaction term, I get identical results. With the interaction, the results are completely different. I'd much appreciate any ...
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How to conduct a capability analysis (by calculating cpk) and check results using Minitab. Six Sigma, DMAIC etc
as the title states I'm conducting a statistical analysis for the variation within a machine (a laser marker). Just as a little background info, I have started off by conducting a GR&R for the ...
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Variance Ratio Test in Minitab
I have two samples, each of size 18 observations. In the first, the SD is 10 and in the second it is 3. I wish to test the hypothesis that the variance ratio is 4, vs. the alternative that it is not 4,...
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Mann-Whitney test W statistics
Below is Mann-Whitney test result from Minitab. At the end of result, there is no p-value but "Cannot reject since W is < 363.0". What does it mean? I cannot ...
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441
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Main effects in Minitab
I have a multilevel factorial design. I use Minitab to study and analyze this design. One of the outcome of such study is the main effect plot. I get the following :
As I am new to design of ...
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MSE in GLM ANOVA
Experimental Design:
Whole plot: Tree species (Spp)
Subplot: Location relative to canopy boundary (In/Out)
Tests: 2-way ANOVA on data collected for several tree species from a transect running ...
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Principal Components Analysis Regression VIF Interpretation in Minitab?
I'm trying to verify my understanding of how to apply principal component analysis to a multiple regression. Here's my current process and understanding using Minitab:
Part 1: I already have my data ...
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