# Wilcoxon

Part 1: Wilcoxon Signed-Rank Test

Let's take a hypothetical situation. The World Health Organization (WHO) wants to investigate whether building irrigation systems in an African region helped reduce the number of new cases of malaria and increased the public health level.

Data was collected for the following variables from ten different cities of Africa:

The number of new cases of malaria before the irrigation systems were built

The number of new cases of malaria after the irrigation systems were built

Table 1: Cases of Malaria

City Before After

1 110 55

2 240 75

3 68 15

4 100 10

5 120 21

6 110 11

7 141 41

8 113 5

9 112 13

10 110 8

Using the Minitab statistical analysis program to enter the data and perform the analysis, complete the following:

Run a sample Wilcoxon signed-rank test to show whether there is a statistically significant difference between the number of cases before and after the irrigation systems were built.

Obtain the rank-sum.

Determine the significance of the difference between the groups.

Determine whether building these systems helped reduce new cases of malaria.

In addition, in a Microsoft Word document, provide a written interpretation of your results in APA format.

Part 2: Wilcoxon Rank-Sum Test

Let us consider another hypothetical situation. The WHO wants to compare the mortality rates of children under the age of five years of underdeveloped and developed regions of the world. There were two independent samples of ten countries from each of the groups drawn at the same time, and the yearly mortality rates of children under the age of five years (per 100,000) inhabitants were reported (MRate1 and MRate2).

Table 2: Mortality Rates of Children

Country MRate1 MRate2

1 120 11

2 110 9

3 105 13

4 61 11

5 45 14

6 114 11

7 118 10

8 138 8

9 85 6

10 70 6

Using the Minitab statistical analysis program to enter the data and perform the analysis, complete the following:

Run the Wilcoxon rank-sum test to show whether there is a statistically significant difference between the mortality rates of children under the age of five years of the regions. Results may be used in making decisions regarding which region needs to receive help to improve the public health issues of morality.

Obtain the difference in the mortality rates and whether there is a statistically significant difference.

In addition, in a Microsoft Word document, provide a written interpretation of your results in APA format.