Question

A sample of nurses with affiliation to private hospitals (affiliation = 0) and to university hospitals (affiliation = 1) was asked to rate their confidence in making the right decisions based on their level of ongoing inservice professional development. Use a Mann-Whitney U-test to determine if the distribution of confidence in each group is the same. The file is the first tab in “nonparametric.xlsx.”

Be sure to always write the null and alternate hypotheses, so that the decision is made in the correct direction. Also, conduct all as two-tailed tests at α = 0.05.

ID	Affiliation	Location	Education	Confidence
1	1	3	0	72
2	1	3	5	65
3	0	4	5	66
4	0	1	4	78
5	0	3	1	81
6	1	2	5	81
7	1	1	2	83
8	1	3	3	74
9	0	4	0	78
10	0	2	2	85
11	0	1	1	85
12	1	3	5	69
13	1	2	0	69
14	1	3	2	79
15	1	4	1	82
16	1	1	5	74
17	0	3	0	85
18	0	4	0	68

Answer 1

I used MINITAB-17 software to solve this question.

Step.1 Enter data in minitab. Two samples in two different columns as follows.

Step.2 Go to 'Stat' menu ---> Nonparametric ----> Mann Whitney. New window will pop up on screen.

Minitab output:

Mann-Whitney Test and CI: Private, University

N Median
Private 8 79.50
University 10 74.00

Point estimate for η1 - η2 is 4.00
95.4 Percent CI for η1 - η2 is (-4.00,11.00)
W = 87.5
Test of η1 = η2 vs η1 ≠ η2 is significant at 0.3284

Hypothesis:

H₀ : Two samples coming from same population.

H₁ : Two sample coming from different population.

P-value for this test is 0.3284 which is greater than 0.05, hence at g% level of significance we accept null hypothesis and conclude that these two samples coming from same population.

It means confidence of nurses affiliated  with private hospital and to university hospital is same.