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
n 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
Social services data on the placement of 108 children under the age of 12 in foster care shows that in 76 cases where family counselling was not employed, the average time in foster care was 78.1 days with a standard deviation of 21.9. In 32 cases where family counselling was employed, the average time was 59.8 days with a standard deviation of 25.3. Does this data support the claim that family counselling reduces the time in foster care for children under 12?
Problem 3
In a large city emergency medical services records indicate that 68% of patients transported to emergency rooms have health insurance. In a sample of 150 patients transported to a particular hospital, 92 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?