The cost of medical care varies in different parts of the United States. A sociologist wanted to conduct a unique study of these medical costs. She randomly sampled doctors in the New England area and asked each doctor where he/she had gone to medical school. She then asked each doctor what he/she charged for the same procedure, a routine well-care physical test. The following gives the charges by four independent samples of doctors who went to medical schools in the four geographical areas of the United States. Went to Medical School
Northest Northwest Southest Southwest
95.00 96.00 90.00 118.00
105.00 117.00 85.00 130.00
123.00 110.00 105.00 120.00
115.00 90.00 70.00 125.00
120.00 95.00 80.00 100.00
117.00 121.00
109.00
At the 0.05 level of significance, test to determine if there are any differences in the average charge for a routine well-care physical test among doctors trained at medical schools in the four geographical areas of the United States.
Check the validity of both assumptions required for analysis of variance, at a 0.10 significance level.
If the null hypothesis of equal population means is rejected, use Tukey’s HSD method, with a 0.10 family error rate to perform all pairwise comparisons.
Answer the following questions for the Test of Normality
a. Null Hypothesis
b. Alternate Hypothesis
c. Significance level of the test
d. Degrees of freedom
e. Pvalue