Ten nurses were randomly selected to test the efficacy of a germicidal hand cream.

Ten nurses were randomly selected to test the efficacy of a germicidal hand cream. Total viable bacterial counts were determined by pressing the fingertips of the nurses onto nutrient agar plates before an 8-hr shift. The cream was applied and the procedure was repeated at the end of the shift. 

Total viable count x 10000

Nurse

Before

After

1

Before 3.61

After 1.04

2

Before 1.82

After 1.41

3

Before 1.98

1.71

4

Before 4.21

After 1.31

5

Before 1.82

After 1.20

6

Before 1.41

After 0.42

7

Before 2.25

After 1.33

8

Before 6.41

After 0.68

9

Before 0.23

After 0.91

10

Before 0.17

After 0.22

Given that the distribution of the difference between before and after counts is normal, what will be the appropriate test for this test?

Select one:

a. Paired Sample t Test

b. Mann-Whitney Test

c. Independent two sample t test

d. Wilcoxon's Test

Which of the following would be an appropriate alternative hypothesis?

Select one:

a. The bacterial count before using the cream is lower or equal to the level after using the cream

b. The cream reduces the bacterial count

c. There is no difference among the bacterial count before and after using the cream

d. The cream increases the bacterial count

What is the calculated statistics value in this test?

Select one:

a. 1.652

b. 2.506

c. 2.292

d. 1.986

e. 1.735

What conclusion can be drawn? 

Select one:

a. The cream didn't reduce the bacterial counts (critical statistics = 1.734, p < 0.05).

b. The cream didn't reduce the bacterial counts (critical statistics = 1.501, p >0.05).

c. The cream reduced the bacterial counts (critical statistics = 1.833, p < 0.05)

d. The cream reduced the bacterial counts (critical statistics = 1.812, p < 0.05).

Some one found that the distribution of the difference between before and after counts is in fact non-normal, what will then be the appropriate statistical test? 

Select one:

a. Kruskal-Wallis Test

b. Mann-Whitney Test

c. Paired Sample t Test

d. Wilcoxon's Test

Based on last question, what is the calculated statistics value for this test?

Select one:

a. 16

b. 39

c. 6

d. 49

Then what conclusion can be drawn?

Select one:

a. The cream reduced the bacterial counts (critical statistics = 8, 0.02 < p < 0.05).

b. The cream didn't reduce the bacterial counts (critical statistics = 8, p > 0.05).

c. The cream didn't reduce the bacterial counts (critical statistics = 10, p < 0.025).

d. The cream reduced the bacterial counts (critical statistics = 10, 0.025 < p < 0.01).