I want to understand whether the differences in the means of two independent samples (distributed lognormally) are statistically significant. In order to use Student's t-test, the data must be distributed normally. Since I have lognormal distribution, do I need to test the data for normality? (Using for example Shapiro-Wilk/Kolmogorov–Smirnov tests).
I know the differance between normal and lognormal distributions (normal distribution is symmetric and lognormal distribution is right-skewed. And lognormal random variable is positive, whereas normal has also negative values).
But I don't really understand whether I have to do test for normality at all. Thank you
I know the differance between normal and lognormal distributions (normal distribution is symmetric and lognormal distribution is right-skewed. And lognormal random variable is positive, whereas normal has also negative values).
But I don't really understand whether I have to do test for normality at all. Thank you