MA207 Final Exam - Takehome Portion
For each of the problems below, use the technology guide to perform a statistical analysis.
You should justify your choice of method, including any assumptions made in the use of the method.
You should indicate whether a two-tailed, left-tailed, or right-tailed analysis is appropriate,
and, in hypothesis testing problems, state the null and alternative hypotheses.
If the problem does not specify a level of significance, you should choose one.
Problem 1
A government health agency estimates the level of HIV infection in a certain area at 15.3%. Testing is performed on a random sample of 45 residents and 12 of the tests are positive. Does this data support the agency figure?
Problem 2
In 2005 Hospital A performed 73 coronary bypass surgeries with an average length of stay of 6.1 days and a standard deviation of 2.3. Hospital B performed 41 similar surgeries and had an average length of stay of 7.3 days with a standard deviation of 3.0. Based on this data, do the lengths of stay for coronary bypass surgery differ significantly for these two hospitals?
Problem 3
In a large city emergency medical services records indicate that 78% of patients transported to emergency rooms have health insurance. In a sample of 50 patients transported to a particular hospital, 32 were found to have health insurance. EMS claims that they do not consider insurance when deciding which emergency room they will transport a patient to. Does this data support their claim?