Consider the following paired samples and their differences.

a. Verify that the median of the sample differences is equal to 0.

b. Compute the test statistic for the signed-rank test.

c. Do you reject the null hypothesis that the median is equal to 0? Use the α = 0.05 level of significance.

Exercise 17 demonstrates that the results of the signed-rank test may be misleading when the assumption of symmetry is violated.

68 59 66 67 64 58 70 71 54 68 Sample 1 50 60 55 74 59 66 55 68 65 82 34 89 97 73 78 Sample 2 80 70 76 76 72 45 56 56 38 51 57 66 60 78 47 63 14 68 75 50 54 62 68 56 68 Differences -12-11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 13 14 15 16 17 18 19 20 21 22 23 24