Question 1

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.

Question 2

In the previous item, we used the Mann-Whitney test rather than an independent t-test. Why might we Mann-Whitney rather than the t-test?

Question 3

In the third tab of the same file (nonparametric_sheets.xslx), there are data for the selling prices of homes in a ZIP code and the square footage of those homes. Use the Spearman rank correlation to determine if there is a significant correlation between the home price and the square footage.

A table of Spearman rank significance values is located in the file.

Question 4

Why did we not just use the Pearson correlation for the previous item? That is, what is the Pearson correlation influenced by that the Spearman is not?

Question 5

A restaurant wondered if there was a difference in the number of refills of soda ordered by those aged 18-24 (age = 0) and those aged 13-17 (age = 1). Use the Mann-Whitney U-test to determine if the distribution of soda refills is significantly different for the two groups.

Question 6

An organization was attempting to determine whether there was congruence between the rating of their hiring personnel in rating new employees during their interview presentations. The file “Spearman 2” to determine the Spearman rank correlation between the judges’ ratings.

Question 7

The following data were collected related to the number of visits to a suburban health clinic.

Month	Visits
January	1610
February	1585
March	1649
April	1590
May	1540
June	1397
July	1410
August	1350
September	1495
October	1564
November	1602
December	1655

The null hypothesis is that the number of visits is uniformly distributed throughout the year. Use a chi-square goodness-of-fit test to determine whether the null hypothesis should be rejected at α = 0.05. Interpret the results.

Question 8

There are 8 job codes in a large hospital system. The table below indicates the number of grievances filed by members of the union by job code. Are the number of grievances uniformly distributed at α = 0.05?

Job Code	Grievances
1	19
2	17
3	14
4	18
5	19
6	21
7	18
8	18

Interpret this for hospital leadership.

Question 9

A research firm was interested in knowing whether income level and location of service for procedures were independent. The following data were provided.

Clinic Hospital Private

<$30,000 85 16 6

$30,000 to $49,999 102 27 13

$50,000 to $99,999 36 22 15

> $99,999 15 23 25

Use a chi-square test of independence to determine whether income level and service location are independent. Test the null hypothesis the service location is independent of income at α = 0.01.

Question 10

Is the preferred beverage ordered at lunch independent of the age bracket in a hospital cafeteria? Test the null that is independent at α = 0.05.

Coffee/Tea

Soft Drink

Other

21-34

26

95

18

35-55

41

40

20

>55

24

13

32