An experiment was made to measure the mean number of axe strikes that is necessary to cut a tree trunk. 16 identical tree trunks were cut by a randomly chosen person. Observation Number of strikes
1 52
2 54
3 49
4 55
5 44
6 47
7 53
8 45
9 46
10 48
11 55
12 57
13 51
14 54
15 56
16 52
a. Use the Wilcoxon signed-rank test to investigate the claim that the median number of strikes is 50. Assume that the alternative is two-sided.
b. Determine the sum of the positive ranks.
c. Determine the sum of the absolute values of negative ranks.
d. Determine the value of test statistic.