I have a big dataset which I divided into different periods (years) and focused on one group. I calculated the means for the different time periods (for at least 3 variables) for this group, and now I want to verify if they are really different.
Is a T-test the most appropriate test if I assume that my data is normally distributed
You can use the t-test if you have two groups to compare, in your case it’s the years. If you have more than two groups, then you have to go for ANOVA. I assume the items were the same across the different years. If you have two groups, in this case the t test for two related samples (dependent t-test) would be the choice. You say you have at least three variables, in this case you might consider doing MANOVA (multivariate ANOVA).
Hope this helps.
These are all means, and I want to know if they significantly differ from y2000. (e.g differs -0,17 significantly from 0,38, differs -0.021 significantly from 0,32, etc)
Is the Manova then still appropriate?
If I try a independent T-test with Stata, he takes all these observations together, but I want to take each observation separate