Return to the data for Practice Exercise 4 in Chapter 5. (a) Test the hypothesis that the change in weights has a distribution that is symmetric to about 0. Compare this result to that for a paired t...

Return to the data for Practice Exercise 4 in Chapter 5.

(a) Test the hypothesis that the change in weights has a distribution that is symmetric to about 0. Compare this result to that for a paired t test.

(b) Test the hypothesis that the median change is 0, without making the assumption of symmetry.

Exercise 4

A closer examination of the records of the air samples in Exercise 3 reveals that each line of the data actually represents readings on the same day: 2.92 and 1.84 are from day 1, and so forth. Does this affect the validity of the results obtained in Exercise 3? If so, reanalyze.