According to http://www.atheistberlin.com/study http://www.atheistberlin.com/study they got a significant Wilcoxon Signed Rank Test at p < 0.01. The Wilcoxon Si

According to http://www.atheistberlin.com/study http://www.atheistberlin.com/study they got a significant Wilcoxon Signed Rank Test at p < 0.01. The Wilcoxon Signed Rank Test is nonparametric (i.e. sacrifices some statistical power in order to not make assumptions about the underlying distribution of the data) so is meaningful even if there is a long tail of packages that take longer due to circumstances outside of the study variable.