t-test

Hi, I am new to the board and tried to search for Hotelling's T but could not find an answer to my problem (the appropriate test statistic). I'm not sure if Hotelling's is the correct stat, or if one exists. Setup: I have two samples of different sizes, A and B, drawn from different...

This has been solved using SPSS

poor design methods

Hi everyone! I am having some troubles with interpreting the significance of mean. Mean= 0.19609 St. Dev=0.12341 n=141 I get t-statistic of 18.86763( ratio mean/ st. error) I thought that for the mean to be significant and expected (not abnormal) t-stat has to be within the interval...

Hi all, I know that paired t-tests are appropriate for the same group of people at several points in time while independent t-tests are for 2 different groups of persons. But what about when it is a combination of both (ie: looking at different people overtime?) 1) I want to compare 2...

Dear all I wonder if anyone can help with this question. I have to log-transformed (log 10) a number of my variables (skewed distributions). My question is, how do I report the statistical test? e.g. if I perform a t-test, do I need to back-transform my means and SD and the t-statistics? If...

Hi, please help me with this simple question that no one at my uni seems to be able to answer! I have 3 groups (n=20) where I'm looking to establish differences pre & post treatment (2 intervention groups, 1 control). All are normally distributed. I have done paired sample t-tests on all 3...

I am conducting a t-test and have to choose between an unmatched and matched test. I am looking at the vaccination percentage rate between men and women in a given year. Would this be a matched test? My understanding is that in a matched test, the two variables need to be independent, but I am...

Hi I was wondering if someone could help. Say I have a sample of numbers 5,6,7,5,6,7,5,6,5,4 and I want to test which of these individual numbers is significantly different from my population mean of 5, how do I go about doing it? I've carried out a t-test and found that the sample mean...

I am interested in testing if the variance of one data set is bigger than another set. I thought about using a simple F-test, but I am not sure the populations are normal. Is there a 1-tailed variant of the Levene Test for Equality of Variances? I understand that the Levene Test performs a...

Hi, I need help in knowing which test to perform with this analysis. I have two groups (lets say group A and B). A study was performed with initial rates of heart failures in group A and B (i.e, baseline rates) were measured. After 6 months of follow up the heart failure rates in group A and...

Dear all, group 1: treatment A group 2: treatment B thickness of the skin was compared between group 1 (n=20) and group 2 (n=20) I have used a non-parametric Mann-Whitney test resulting in a highly significant difference. Now, the reviewer of my paper has rejected the submission...

How can I calculate the t-values of the regression coeffs if I have the sample size and the correlation matrix only? Is this possible? Thanks in advance.

Hi! I'm really, really hoping someone can help me with this, because I've been trying to figure it out on my own, and I'm getting NOWHERE. Here goes: I'm a student working on a paper regarding the use of cholesterol- lowering meds and cholesterol-leves in blood. My paper is basically...

Hi, I would like to compare two groups, one treated, one control. Usually, I would simply use a t-test, assuming normal distribution and equal variance. However, I would now like to use another parameter as a co-factor: I am comparing two groups of animals and the effect I observe...

Hi all, I've just run a three-way ANOVA on my data (3 IVs, 1 DV). I've got some main effects, as well as a three-way interaction effect. Am I supposed to run t-tests after the ANOVA in order to work out where the significant interaction effect is stemming from? Thanks