For the following assignment, use the Rank Correlation. Utilizing Excel or SAS:
- Use a rank correlation coefficient to test for a correlation between two variables.
- Use a significance level of α=0.05.
The new health care program in the United States makes provisions for capitation programs where health care insurers work with clinical facilities to perform risk analysis of patients to determine the cost of providing care. The following assignment might be used to assess how much a person smokes.
When nicotine is absorbed by the body, cotinine is produced. A measurement of cotinine in the body is therefore a good indicator of how much a person smokes. The reported number of cigarettes smoked per day and the measured amounts of cotinine (in ng/ml) are provided. (The values are from randomly selected subjects in a National Health Examination Survey.) Is there a significant linear correlation? How would you measure the cotinine level in the body? Explain the result.
Refer to the "Rank Correlation Table."
Rank Correlation Table
|
x (cigarettes per day)
|
60
|
10
|
4
|
15
|
10
|
1
|
20
|
8
|
7
|
10
|
10
|
20
|
|
y(cotinine)
|
179
|
283
|
75.6
|
174
|
209
|
9.51
|
350
|
1.85
|
43.4
|
25.1
|
408
|
344
|