(Onsider the null hypothesis that flooding has no effect on ATP level in river birch. This hypothesis could be tested in two ways: as a contrast (using the method of Section 11.8), or with a two-sample t test (as in Exercise 7.2.11). Answer the following questions: do not actually carry out the tests.
(a) In what way or ways do the two test procedures differ?
(b) In what way or ways do the conditions for validity of the two procedures differ?
(c) One of the two procedures requires more conditions for its validity, but if the conditions are met, then this procedure has certain advantages over the other one. What are these advantages?