I comparing fish diversity from the years 2013 to 2018 in a freshwater river system. There are however different species present in some years. Can I still use the Shannon Index to compare diversity? I have attached my calculations below.

Thank you!]]>

I have added a second data set to a set originally set up by someone else. The data includes multiple psychometric tests so calculate variable was used for scoring. This has not calculated the new data rows added automatically so I believe I have to set up a new variable to include ensure the new data is calculated. Is there a way to see what the calculations were in the previous variables set up to score the data? Hop this makes sense???]]>

You hear that a study (randomized, controlled trial with two groups) found a small sized effect of a drug (n = 72) against placebo (n = 72) of d = 0.2. Is this effect significant with α=0.05? (You can solve this problem just by looking at the formulae. You should not need the help of a computer.)]]>

Just need to ask a question regarding the calculation of Inventory Turn Over Ratio and DOH for quarter (90 days) as I used the turnover ratio to determine if this item is Fast, Slow or Non moving item

I have two areas, One is the Area Stores which sell the inventory, and the second is the main warehouses which issue the goods to the Area store (the stock in this area isn't sold).

I used the COGS/Avg. Inv. in Area stores to...

Inquiry about DOH, Turn over Ratio and FSN Analysis if Inventory on hand = zero]]>

I would like to compare two dichotomous variables:

1) pass/fail for a statistics test before statistics class (pre-test)

2) pass/fail for a statistics test after statistics class (post-test)

I only have data on pass/fail (so dichotomous and not able to retrieve interval measure; therefore not able to execute a dependent t-test)

As my fellow students filled in the test anonymously I am not able to pair/match results of the pre-test and post-test (so I am not able to execute a...

Comparing two dichotomous variables (non-paired)]]>

I have a B.S. in biology and I'm currently working as biologist. I am wanting to pursue a master's degree in statistics and there are several online programs that look intriguing. A couple of them are M.S. degrees and one (the one I like the best) is a M.A.S. All of them are applied statistics degrees. I'm not sure which one is better. I've read that the M.S. is more theoretical and is better if I pursue a phd. At this point in my life I don't plan on doing that.

Which is better, a...

M.S. vs M.A.S. in Applied Statistics for future career]]>

Z vs. t TESTING

The question: µ 1 = µ 2?

Z testing provides an estimate of the probability that µ 1 = µ 2.

The statistic used is

In practice,

s is a biased = incorrect estimator of σ.

s < σ.

s approaches σ as n approaches ∞.

It is generally agreed that s is acceptably close to σ at n > 30;

that (x̄ 1 - x̄ 2) / (s / √n) is acceptably close to (x̄ 1 - x̄ 2) /...

Z vs. t TESTING]]>

The "X"-data are averages of about 50 time series having clear trends of various shapes, mostly convex and/or increasing; i.e. they are autocorrelated. Each time series has in median 45 values. The...

Need help to correctly bootstrap confidence interval for correlation of 50 y-values against 50 averages from autocorrelated subsets of 2000 x-values]]>

I am doing a longitudinal multilevel analyses.

I am researching the impact of certain restricting abortion policies of US states on the number of abortions. Furthermore I control for the characteristics of these states.

One of these characteristics namely poverty rate of a state, has a negative significant correlation with number of abortions. (So a higher poverty rate in a state, correlates with lower rates of abortions)

Yet when introduced as a controlvariable in the multilevel...

Negative correlation, but positive effect in multilevel regression]]>

I need to know how to solve and write down for those solution.

Thank you]]>

I'm just a uni student suffering from covid-struct regression lessons (getting help for questions is not easy). I hope I could get some answers from here..

I'm doing OLS regression with to goal to see effects of certain cryptocurrency on-chain factors on the price differences of a cryptocurrency.

E.g. model is the sort of

Price of crypto = B0 + B on-chain factor + e

All the variables are daily data in logarithmic first difference for stationarity and do not contain unit roots...

OLS time series regression, importance of autocorrelation?]]>

I am currently doing a Research project and am unsure if its possible to assess significance. In my project, I have looked through the CT scans of 200 patients for certain findings (lets call them Feature A, B , C etc.). After totalling up the number of each type of finding, I wondered if its possible to assess whether, for example, finding Feature A in 45/200 patients is significant? Can I assess whether these findings are significant within my sample, or is it only...

Is it possible to use a statistical test on my population sample?]]>

23 have respiratory allergy

By 12 patients allergy is excluded

7 are suspect

Is the frequency of respiratory allergy statistically significant?

What type of test should we use in this example?]]>

I am trying to perform a GLMM with my simple dataset. I have 2 blocks divided each in 2 plots and in each plot I have my samples units that are trees in this case (5 trees, and for each one I have a specific measurement)). I would like to run a GLMM to see if I got some differences between plots and between blocks and I would like to set the tree as random factor such as : Block(plot(tree)). I got a warning message:

glmm: The final Hessian matrix is not positive definite although all...

GLMM what can I do when parameter of residual effect is redundant? Any advice?]]>

I am writing a project proposal: randomized, placebo-controlled crossover trial, I will be investigating treatment vs air. Participants will be asked to inhale the treatment or high-flow air (placebo). In this case, would a one-tailed test or a two-tailed test be more appropriate? Furthermore, the primary endpoint will be the time to onset of pain relief - which would be the best statistical tests?

My statistical competency is not so great. I, therefore, appreciate the help and do...

Stats help - please!]]>

I am going to be carrying out a study, however, there is insufficient data to inform us of some information to calculate the sample size. Would be best to use effect size to calculate the sample size then?

Thank you in advance,]]>

I have been told that a binomial logistics regression analysis is what I need to do. I wanted to check this is correct and secondly to check that I am doing the...

What is the right test for my research question?]]>

I have been assigned with the data analysis on some marine science research, but I am by no means an expert. I was hoping to get some advice on what test I should use as well as how I should set up my data. I think I need to use a one-way ANOVA but am not sure. My research question is: Is there a significant difference in the amount of fish between different artificial reef types? The details of the data set are:

-5 different surveys, each split into two days (the...

Marine science research test help]]>

I am doing a research project and am having trouble finding the correct statistical analysis for my data.

I would like to test whether gene length is different between plant species that grow in two different habitats. I chose 12 species from each habitat and sequenced almost all (17000) genes from each species, and measured the length of each gene. I was planning to do a linear model like this: (length ~ habitat + species) but since each species is found in only 1 habitat, I am...

Comparing groups with subcategories]]>

I am trying to model a quality of life score that has a range [-0,158 ; 1], where values equal to one indicate the patient is fully healthy, values equal to 0 indicate the patient is dead, values smaller than 0 indicate a health state that is worse than death.

I assume general linear regression is not suitable since my response variable can always go outside the response range depending on the values of the covariates.

What is the suitable model parametrization to make...

modeling an outcome that has a range from [-0.158 ; 1 ]]]>

I wish to know if I can go back and look at my data and determine how random was the pairing of machines used for measurements.

Hopefully it becomes clearer by looking at the table below:

Looking at the table you can see that 4 measurements were made on machine 1 indoors (red) while at the same time 4 measurements were made on machine 6 outdoors (red). Similarly 2 measurements on were made on machine 5 indoors (grey) while at the same time 2...

Can you look retrospectively at how random paired measurements were?]]>

I'm working with panel data, a fixed effects model, and I'm testing an inverted

The thing is now I want to

1...

Inverted U-shape and moderation]]>

I want to prepare my dataset for a LMER model conducted using Statsmodels in Jupyter Notebook. I have crossectional and longitudinal data, and have therefor been advised to use LMER. But I need help to understand how I should structure my collected data in a csv file.

My dataset contains 11672 observations regarding 14 different stocks measured over a time period of 15 days.

For each day I have collected information about the traded

Structure dataset for LMER-model]]>

currently I'm doing research about the relation between body weight and the social status of children, but I'm stuck. I hope somebody can help me with the interpretation of the interaction terms in SPSS. Below I explain my model and my hypothesis briefly:

I hypothesize that girls are more vulnerable for status loss than boys if they are overweight or obese.

The model that I build is as follows:

- Social status is my dependent variable. (range is 1.00 - 5.00 (1 means very...

Interaction in linear regression]]>

Whilst this isn't home work but work related, been a long time since I have brushed on my statistics but spent some time here trying to look at some posts and probably has confused me more. I am required to calculate probabilities of failing KPI's/event occurring 'x' amount of times per year. A couple of examples.

Task 1: "I will fail to produce my monthly report"

My assumption: "I think I will fail this 2 times per year".

Task 2: "I will forget to return client calls"

My assumption...

Probabilities]]>

I have collected data to test the effectiveness of an intervention in reducing waiting times. So, I have pre-intervention population waiting times and post-intervention waiting times. I used an independent samples t-test to compare the pre and post intervention waiting times and all is well.

I collected data mentioned above at 2 different locations. How do I merge the results for the two locations. Is there a statistical test that can allow me to do that?

Thanks in advance.]]>

What is my formula?]]>

I have some data of tree mortality registered each 3 month. In the same date I registered sign of dryness, insect folivory or mammal predation (The plants were not always found dead with these signs). I would like now to analyse the data with SPSS and determine which of these signs are more responsible for tree death. My dataset structure is: dead 0/1, dryness 1/0, insect 1/0 etc. and I was thinking doing a survival analyse with Cox's proportional hazards.

This kind of issue always...

how to analyse underlying multiple causes of death data]]>

I am currently doing a Research project and am unsure what test I should use to test statistical significance. I am trying to assess whether certain findings on a CT scan appear more frequently in a specific group of patients (present with a chest pain), compared to a control group (don't present with chest pain). This can be then used to support my hypothesis that patients with chest pain but no heart disease may have something else wrong (visible on CT) that could explain...

Comparing two groups with categorical data- Need help in choosing the correct stat test to assess significance]]>

I'm a total beginner in SPSS, first time user.

I'm having an issue with a survey I'm conducting, I've changed string > numeric using recode.

Answers were on the Likert scale and changed to 1-5.

However, I've noticed that when I go into analyzing process, the answers for the each individual has changed.

It's like it's not connecting the value for it to the numeric but the row of it, so if a individual picked the first answer it will assume it's the numeric value of 1 which is not...

Changing values from string to numeric - Affect on answers in survey]]>

The overuse of percentages by our wise ruling class and media to convey critical information may be hindering understanding, and therefore a rational response to the

WANTED: Rational Coronavirus Analysis]]>

I am a bit confused about the statistical analysis I should perform on my data (when I have it). I have been advised to do a multi-level modelling but I can't seem to get everything to fit and make sense. Alternatively, I have thought about doing a multiple regression. The measures are made up just to give an idea...

My IV is the score on an anxiety test and the three levels are control , at-risk and clinical.

My DVs are IQ score, performance on a breathing exercise and...

1IV with three levels and multiple DV's - Appropriate analysis?]]>

Total number of obs = 981

Model 1: y = b0 + b1x1 + b2x2 + b3x2

Model 2: y = b0 + b1x1 + b2x2 .... + b5x5

How do I compare the two regressions? Is using the difference in F-values for both models, with df1 = 2, and df2 = 975 (981-6)?]]>

Kindly request some help with the following:

My dataset includes many date variables, and I would like to find the variable which is nearest to 1 specific date variable (=treatment in example below). Is there a way to achieve this (like for example variable Nearest below)? And if so, how?

Example: (Date=ddmmyyyy)

id treatment QA1 QA2 Q3 Nearest

case1 04-08-2020 02-07-2020 20-08-2020 13-09-2020 20-08-2020

case2...

Find nearest value among multiple variables]]>

Also, how would you call a model like this? To be extra precise, I am also including covariates and different measurement levels in...

Combining mediation and moderation in linear model (SPSS, PROCESS)]]>

proc mixed data=***.likinggroupsavg;

class group judge week motive3 diff3;

model like=group|week|motive3 group|week|diff3 thirsty;

random intercept / subject=judge;

repeated week / subject=judge type=AR(1);

LSmeans group|week|motive3 / diff slice=week;

LSmeans group|week|diff3 / diff...

Help with mixed model code]]>

I wanted to recreate a research for my country so I used their model and ran EFA on my data and determined the factor loadings. (SPSS, principal axis factoring, varimax)

The research says that they did Ordinary least squares regression to determine effects in the model, for this they say 'the item scores for each factor were averaged to form the variable for that factor, we mean centered the independent variable and the moderator variables before taking the multiplication'...

Please help with ordinary least squares]]>

I am trying to see how the motor time of a response to a stimulus (DV: quantitative, continuous) evolves based on difficulty level of the task (IV: 8 levels, categorical).

My hypothesis is that motor time will increase, then decrease (inverted U shape).

I conducted a RM ANOVA (using the Greenhouse-Geisser correction, as the scphericity assumption was violated) and polynomial contrasts using JASP, but the RM ANOVA is significant without the GG correction, but non-significant...

Polynomial (quadratic) contrasts: clarifications & inverted-U]]>

i is linear, iii is not linear, that's fine.

But the solutions to this claim that ii IS linear.

I think that it is not because alpha and beta and raised to different powers.

Can anybody give an opinion on this?

Thanks!

]]>

"A particular supplier guarantees a quality level of 99%. You recently purchased 100 components. You have built 50 subassemblies which require 1 component each. In the 50 subassemblies, you found 3 defective components. What are the chances that this could happen randomly."]]>

I'm hoping someone can help me. I am conducting research for my thesis looking at relationship between social connectedness (IV), and diabetes distress, diabetes self-management and perceived competence (DVs). All are continuous variables measured on self-report likert scale questionnaires.

I am interested in understanding how social connectedness influences outcomes and struggling with the best way to do this. At first I thought MANOVA however due to splitting my data set into...

Which test to use? one predictor variable and 3 dependent variables]]>

CONSORT is quite emphatic about the reporting of effect sizes. However, SPSS does not produce these for linear mixed models, as far as I am aware.

Also, I have not seen many papers report them either. The one that I have references this paper as to how they calculated them...

Are effect sizes required when reporting a Linear Mixed Model? If so, how are they calculated?]]>

I'm studying the predictors of the adoption of a methodology in firms with a binary logistic regression with data for 4 years (panel data). The firms that adopt this method Y=1 and 0 otherwise.

The problems that I have are that:

i) My

ii) My two study variables are continuous. One is country-level (same value for each of the 8 countries) and the other study variable has...

Model for pannel data with clusters]]>