M
mi06rasja
Hi
I have a question for you guys regarding paired t-test. I am currently working with measuring vibration on a machine at different rpm. What I do is that I measure the vibration at different rpm and by that I get a curve which tells me how the machine vibrates. I can also see any natural frequency?s with this approach.
However, we have now made some plausible improvement but it?s quite hard to see them using the approach above. So in order to make correct assumption I am trying to make a paired t-test with 95% significance level. But when I am reading about the t-test in my textbook it says that both data need to be normally distributed. If both data are non normal it says that i should use Wilcoxon test instead. The before and after data are however not normally distributed but the differences between them are normally distributed. So my question to you are if I should use a one sample t-test of the differences or if i should use a Wilcoxon test instead?
I have a question for you guys regarding paired t-test. I am currently working with measuring vibration on a machine at different rpm. What I do is that I measure the vibration at different rpm and by that I get a curve which tells me how the machine vibrates. I can also see any natural frequency?s with this approach.
However, we have now made some plausible improvement but it?s quite hard to see them using the approach above. So in order to make correct assumption I am trying to make a paired t-test with 95% significance level. But when I am reading about the t-test in my textbook it says that both data need to be normally distributed. If both data are non normal it says that i should use Wilcoxon test instead. The before and after data are however not normally distributed but the differences between them are normally distributed. So my question to you are if I should use a one sample t-test of the differences or if i should use a Wilcoxon test instead?