Hi everybody,
I am comparing 4 independent groups of data. All groups have a normal distribution while one of them is not normally distributed. My question is: how we can compare these four groups?
**if the problem cannot be solved by transforming the data, what should I do?
Thanks
What do you mean by comparing groups? Can you please provide some details about this part. I mean what are the comparison parameters?
Hi everyone,
I need to evaluate the effect of four different media on removing Nitrate. I took ten water samples from the outlets of four rectors containing different media and processed them for Nitrate. I want to use one-way anova to compare these four group data, but before that I need to know whether each group data is normally distributed or not. I used Shapiro–Wilk test and found three groups of data were normally disturbed while no-normal distribution was found for one group of data. I used both log and square root transformation, but none of them worked. Now, the question is in this case can we use non-parametric tests to compare these four groups of data? or to better ask, which statistical test can be suggested in this case?
Bests,
I think you try Taguchi statistical approach for optimization study of different variables