The authors of the paper “Delayed Time to Defibrillation after In-Hospital Cardiac Arrest” (New England Journal of Medicine [2008]: 9–16) described a study of how survival is related to the length of time it takes from the time of a heart attack to the administration of defibrillation therapy. The following is a statement from the paper:
We identified 6789 patients from 369 hospitals who had in-hospital cardiac arrest due to ventricular fibrillation (69.7%) or pulseless ventricular trachycardia (30.3%). Overall, the
Data from the paper on time to defibrillation in minutes) for these 6789 patients was used to produce the Minitab output and boxplot at the bottom of the page.
- a. Why is there no lower whisker in the given boxplot?
- b. How is it possible for the median, the lower
quartile , and the minimum value in the data set to all be equal? (Note—this is why you do not see a median line in the box part of the boxplot.) - c. The authors of the paper considered a time to defibrillation of greater than 2 minutes as unacceptable. Based on the given boxplot and summary statistics, is it possible that the percentage of patients having an unacceptable time to defibrillation is greater than 50%? Greater than 25%? Less than 25%? Explain.
- d. Is the outlier shown at 7 a mild outlier or an extreme outlier?
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