Southside Hospital in Bay Shore, New York,
commonly conducts stress tests to study the heart
muscle after a person has a heart attack. Members of the diagnostic
imaging department conducted a quality improvement
project with the objective of reducing the turnaround time for
stress tests. Turnaround time is defined as the time from when
a test is ordered to when the radiologist signs off on the test
results. Initially, the mean turnaround time for a stress test was
68 hours. After incorporating changes into the stress-test
process, the quality improvement team collected a sample of
50 turnaround times. In this sample, the mean turnaround
time was 32 hours, with a standard deviation of 9 hours.
a. If you test the null hypothesis at the 0.01 level of significance,
is there evidence that the new process has reduced
b. Interpret the meaning of the p-value in this problem.
The solution provides step by step method for the calculation of testing of hypothesis. Formula for the calculation and Interpretations of the results are also included. Interactive excel sheet is included. The user can edit the inputs and obtain the complete results for a new set of data.