- Applications
AIDS Cases
Acquired immunodeficiency syndrome (AIDS) is a specific group of diseases or conditions that indicate severe immunosuppression related to infection with the human immunodeficiency virus (HIV). According to the HIV/AIDS Surveillance Report (11(2)), the number of AIDS cases in the United States for 1999, by gender and race/ethnicity, is shown in the following contingency table. Use this information to determine, at the 1% level, if the distribution of males into the four race/ethnic categories differs from the distribution of females into the four groups.
| White | Black | Hispanic | other | |
|---|---|---|---|---|
| Male | 12855 | 14946 | 7019 | 439 |
| Female | 1924 | 6784 | 1948 | 103 |
Distribution of Cyprinids in Asia
Researchers in Asia (Roberts, 2000) wanted to describe the distribution of the fish genera Cyprinidae in Asian rivers. They collected 228 fish from the Brahmaputra, Irrawaddy, and Salween rivers and recorded whether the fish was a member of the Cyprinidae family or not. Because the rivers were relatively equal in size, they expected the same proportions of Cyprinidae in each of the rivers. Using the data in the table below, test to see if there was a difference in the proportion of Cyprinidae among the rivers at the 5% level.
| River | Cyprinid | Not Cyprinid |
|---|---|---|
| Brahmaputra | 22 | 51 |
| Irrawaddy | 25 | 53 |
| Salween | 30 | 47 |
Working Environment for Nurses
The American Nurses Credentialing Center (ANCC) has created guidelines for nursing administration. Some research findings have suggested that ANCC-recognized hospitals also have favorable practice environments for nurses. To study this further and in relation to oncology units, Friese (2005) examined the practice environments and outcomes of nurses working in and out of oncology units in hospitals that adhere and don’t adhere to the ANCC guidelines. As part of his study, he determined, through surveys, whether nurses were experiencing high emotional exhaustion (HEE) or not. The results of his study are shown in the table below. Use these results to determine, at the 5% level, if the proportion of nurses experiencing HEE differs among the four categories of hospitals.
| Clinic Type | HEE | not HEE |
|---|---|---|
| non-ANCC, non-Oncology | 362 | 534 |
| non-ANCC, Oncology | 58 | 92 |
| ANCC, non-Oncology | 197 | 558 |
| ANCC, Oncology | 30 | 125 |
Sex Effect on Heart Attack Deaths
Fiebach et al. (1990) examined the immediate survival of 790 males and 332 females who were hospitalized following a myocardial infarction (i.e., a “heart attack”). During hospitalization, 70 men and 47 women died. Is there a difference, at the 5% level, in mortality rate (proportion of patients that died) between men and women during hospitalization?
School Uniforms
Ashland High School conducted a survey to determine if parents or students favored the idea of uniforms being required apparel for attending school (December 5, 1999, Ashland Daily Press). The surveys were administered to 223 parents at parent-teacher conferences and to 572 students by the Student Council. No other information about the surveys was given in the report. From these surveys it was learned that 70 parents and 101 students FAVORED the wearing of uniforms. Determine, at the 5% level, if there is a difference in the level of support for wearing uniforms between parents and students.
Arthritis Pain Relievers
Five hundred patients participated in a comparison of the effectiveness of three arthritic pain relievers (175 received medication A, 150 received medication B, and 175 received medication C). Each patient used one of the three medications for one month and then was asked if the product was effective. The results showed 115 patients using medication A, 78 patients using medication B, and 140 patients using medication C said their medication was effective. Test, at the 10% level, if there is a difference in effectiveness among the three medications.