# Questions tagged [minitab]

Commercial statistical package distributed by Minitab Inc.

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### Math behind the standardized effects from Minitab

I would like to understand the mathematics behind the Standardized effects (SE) as found in, e.g., Minitab. I'm far from an expert in statistics, but I found this page which treats the same question. ...
1 vote
30 views

### Trying to construct Response surface involving unequal variance for the data mentioned using Minitab [closed]

I'm new to Minitab and I never learned statistics as a proper subject. I need to get a response surface and CI for a factorial experiment for my thesis. I'm faced with what looks like unequal and ...
1 vote
113 views

### 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-...
69 views

### 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 ...
1 vote
14 views

### 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. ...
29 views

### 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. ...
28 views

### 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 ...
176 views

### 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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1 vote
120 views

### 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 ...
100 views

### 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 ...
62 views

### 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 ...
199 views

### 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 ...
143 views

### 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 ...
46 views

### 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 ...
1 vote
190 views

### 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 ...
508 views

### 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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27 views

### 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 ...
2k views

### 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 ...
1k views

### 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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512 views

### 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 ...
1 vote
307 views

### 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 ...
41 views

### 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....
282 views

### 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 ...
86 views

### 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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10k views

### 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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220 views

### 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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1 vote
294 views

### 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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587 views

### 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 ...
1 vote
2k views

### 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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1 vote
108 views

### 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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867 views

### 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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1 vote
99 views

### 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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110 views

### 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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1 vote
24 views

### 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 ...
1k views

### 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 ...
1 vote
1k views

### 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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275 views

### 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 ...
1 vote
56 views

### 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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1 vote
57 views

### 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 ...
• 11
720 views

### 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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1 vote
2k views

### 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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73 views

### 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, ...
1 vote
2k views

### 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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1 vote
423 views

### 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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751 views

### 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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3k views

### 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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129 views

### 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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1 vote
308 views

### 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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