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1. Sample size calculation

Dear all, 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,

Hello, i need some help with an assignment. we have two random variables x1 and x2. E[x1]=E[X2]=1, VAR[X1]=4 and VAR[X2]=5. Y=1/3(3X1-6X2) Find VAR[Y], I think I have to just do this: 1/3(3*VAR[X1]+6*VAR[X2]) and get: 1/3(3*4+6*5)=14 EDIT: COV[X,Y]=1 Can anyone confirm or explain my...

Hello, i need some help with an assignment. we have two random variables x1 and x2. E[x1]=E[X2]=1, VAR[X1]=4 and VAR[X2]=5. Y=1/3(3X1-6X2) Find VAR[Y], I think I have to just do this: 1/3(3*VAR[X1]+6*VAR[X2]) and get: 1/3(3*4+6*5)=14 Can anyone confirm or explain my mistake if it's wrong...
4. what sample size is needed for a 99% confidence interval and .025% margin error

As a manufacturer of golf equipment, the Spaulding Corp. wants to estimate the proportion of golfers who are left handed. (The company can use this information in planning for the number of right handed and left handed sets of clubs to make) How many golfers must be surveyed if we want 99%...
5. Desperate for help => Poisson regression or simple non-parametric test?

Dear Community, Hopefully, an easy question to answer! Thanks for picking up this thread. I'm doing an evaluation on whether the use of a digital health tool (MyHealth app) changes the utilisation of healthcare services and am stumped on how to do the analysis. We have 4 groups, based on usage...
6. ANOVA? Looking at percentage habitat use (6 different habitats) across four seasons

Hi, I am trying to look at whether habitat use of 6 different habitat types differs across 4 seasons. I have managed to run ANOVA tests but I'm not convinced this is correct. The code I have been using is as follows; an.aov=aov(Month~Heathland) an.aov summary(an.aov)...
7. Comparing habitat use across two different locations - mann whitney U?

Hi, I'm really stuck with what test to use with my data. I have data on habitat use of 6 different habitat types across 2 locations and I'm unsure what test is most suitable. I thought initially mann whitney U but this doesn't seem to be working for me. I've attached the table below so you...
8. Which test should I run using SPSS ?

Question: Which (in) accuracy is the waist circumference (LEO) of a grown man be predicted based on its fat (VETP)? Which (in) accuracy of the waist circumference (LEO) of a mature man can be predicted based on the total energy consumption (EAVT)? --> Perform these analyzes for both...
9. spss independence tests

hi, i have 3 qualitative latent variables, each of these variables is composed of 4 sub variables two of the latent variables are independent one is dependent i want to test the impact of the IV on the DV and to test the link between both two IVs and whether this link has an impact on the...
10. Need assistance choosing the correct test for two nominal variables.

Hi! I have a single sample and asked them to think about their best and worst experiences in a class project. They answered identical sets of questions when considering the best project and again when considering the worst project. Here are the question examples: When thinking about your...
11. Error: (2067) The Excel file is password protected. Unable to open the file.

Hello everybody, For my study I have to use SPSS. I used an online survey tool where I had the opportunity to download the result in an Excel file. Thereafter I tried to open the file in SPSS. However, it keeps showing the error 'Error: (2067) The Excel file is password protected. Unable to...

I have attached my practice sample final for my college statistics course on linear regression. All of the answers are multiple choice, and I need help finding the right answers for questions 5-39 as soon as possible. Please, please, help me if you can, as soon as you can! I need the right...
13. Trouble comparing variables in SPSS to one set of rules

Hi guys! I am a little puzzled. :confused::confused: I am carrying out research on cyclists perceived benefits of the supplements they take and comparing them to what is scientifically proven. So far I have inserted all my data into SPSS and I have grouped all the variables accordingly...
14. Genstat help

Genstat input - which structure should I use? Hi all, I'm doing a statistics unit as part of my uni degree and I'm having some trouble with an assignment question. We were given a set of data to analyse and I cannot work out which way to put it in genstat. All the options I've tried give the...
15. Why are these statements false?

Hello, I was doing a practice test and I got two questions wrong. The answer key said that these two statements were false: As sample size increases, the standard deviation of the sampling distribution and the standard deviation of the population are increasingly similar. -and- For the...
16. Probability help

never mind, solved it
17. Mixed ANOVA help?!

Hello, I have a 2x2 (Scene x Valence) ANOVA with Scene (Scene1, Scene2) being WS and Valence (Positive, Negative) being BS. For each scene people read a description (which differs by valence) and answer DVs. I did not want the Valence of Scene 1 to affect Scene 2 so for every person, if...
18. Non-Parametric Analyses. Report medians and 95% CI in graphs?

Okay so, I'm currently writing my thesis, and I have to do non-parametric tests. I know that I have to report the medians in text. However, I'm doing graphs. Just wanted to ask whether anyone knows if I report the 95% CI and the medians in the graphs? When i do this it looks super weird and...
19. Running non-parametric repeated measures analysis with split file on

Okay so, I'm currently writing up my thesis, and I've got 2 between group variables and 3 within-group variables. I'm not doing a mixed design ANOVA because my data is non-normal (I'm all okay with doing non-parametric). What my main question is, is whether it is okay to run say a...