Recall Exercise 1.5.31 on cardiac arrests for kidney disease patients. Besides the Monday-Wednesday-Friday schedule for dialysis, many patients are on a Tuesday-Thursday-Saturday schedule. Again, like Monday, Tuesday is unique in that there is the same preceding two-day gap in dialysis. The researchers found that of the 190 cardiac arrests that took place for patients on the Tuesday-Thursday-Saturday schedule, 65 of them occurred on Tuesdays. Do we have convincing evidence of a larger probability of cardiac arrests occurring on Tuesdays compared to the other two days? Investigate by answering (a)–(f). 

a. Stating the hypotheses in words and in symbols. 

b. Give the value of the statistic. 

c. Are the validity conditions met? Explain. 

d. Use the One Proportion applet to give both a simulation-based p-value. 

e. Use the One Proportion applet to also report a theory-based p-value. 

f. Write out a conclusion in the context of the research question.

Data from Exercises 1.5.31

 Patients with kidney disease often have a procedure called dialysis done to clean their blood if their kidneys can’t do this properly. This procedure is often done three days per week, with Monday, Wednesday, and Friday often being those days. In terms of the dialysis treatments, these days are all the same except for the gap of two off days before the Monday treatment. Does this gap make a difference? Cardiac arrest and sudden death for patients undergoing dialysis for kidney disease are possibilities. In recent years, it has been noted that these types of patients have cardiac arrests on Mondays more often than what would be expected. A study published in Kidney International (Karnik et al., 2001) looked at 205 dialysis patients that had cardiac arrests on Monday, Wednesday, or Friday, the same days they had dialysis. They found that 93 of these happened on a Monday. Do we have convincing evidence of a larger probability of cardiac arrests occurring on Mondays compared to the other two days? Investigate by answering (a)–(f).