Question

5. A researcher is conducting a study on the palliative care of patients at a specific facility to determine how their chronic pain symptoms change after entering the palliative care environment. This study is aimed at determining the effectiveness of a standardized treatment protocol for the patients entering into the palliative care environment. To do this, the researcher is comparing the pain scores of individuals before treatment and after treatment. Set up a Wilcoxon signed-ranks test and interpret it at the alpha equals .05 level.

Patient	Before Treatment	After Treatment	Value of Differences	Ordered Absolute Values of Differences	Ranks	Sign Rank
1	9	4
2	10	5
3	7	3
4	8	5
5	6	7
6	9	5
7	6	4
8	7	3
9	9	4

A) We fail to reject H_0, which states the median difference in the pain scores before and after treatment are equal because 40 is less than the critical value 6 for a Wilcoxon signed-ranks test with a population of only 11 individuals.

B) We fail to reject H_0, which states the median difference in the pain scores before and after treatment are equal because 40 is greater than the critical value 6 for a Wilcoxon signed-ranks test with a population of only 11 individuals.

C) We reject H₀ in favor of H_1, which states the median difference in pain scores before and after treatment are not equal because 5 is less than the critical value 6 for a Wilcoxon signed-ranks test with a population of only 11 individuals.

D) We reject H₀ in favor of H_1, which states the median difference in pain scores before and after treatment are not equal because 5 is greater than the critical value 6 for a Wilcoxon signed-ranks test with a population of only 11 individuals.

Answer 1

Result Details

W-value: 1
Mean Difference: 2.89
Sum of pos. ranks: 44
Sum of neg. ranks: 1

Z-value: -2.5471

Sample Size (N): 9

Result 1 - Z-value

The value of z is -2.5471.

Note: N (9) is not large enough for the distribution of the Wilcoxon W statistic to form a normal distribution. Therefore, it is not possible to calculate an accurate p-value.

Result 2 - W-value

The value of W is 1. The critical value for W at N = 9 (p < .05) is 3.

The result is significant at p < .05.

we reject the null hypothesis