# Question: What is the difference between the null hypothesis tested by

What is the difference between the null hypothesis tested by the Mann–Whitney test and the corresponding t test?

## Relevant Questions

What is the difference between the null hypothesis tested by Wilcoxon’s matched-pairs signed-ranks test and the corresponding t test? For the data in Exercise 20.5 we could say that 3 out of 10 residents used fewer hypotheses the second time and 7 used more. We could test this with x2. How would this differ from Friedman’s test applied to those data? Referring to Exercise 20.5, (a) Repeat the analysis using the normal approximation. (b) How well do the two answers agree? Why don’t they agree exactly? Compute the weighted mean risk ratio across the four studies. Three of the studies referred to in the previous exercises also looked at ratings of ADHD severity. These results follow: (a) Compute the mean effect size from these studies. (b) Compute confidence limits on the mean effect ...Post your question