MA145 Final Exam - Takehome Portion
For each of the problems below, use the MA145 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
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 2
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, 35 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?
Problem 3
During the tenure of a certain majority leader, a random sample of 40 votes showed that 94% of the votes cast by members of the majority party were in accordance with the preference of the majority leader. On the first 38 votes following the appointment of a new majority leader, conformance with the party line was 90%. Considered as a random sample, do the first 38 votes suggest that the level of conformance has changed?