The timing of various stages in the contraction of the heart, determined by electro-cardiogram (EKG), can be used to diagnose heart problems. A commonly measured time interval in the contraction of the ventricles is the socalled QRS wave. A study was conducted to see if longer QRS times were related to the ability to induce rapid heart rhythms (called inducible ventricular tachycardia or IVT), which have been associated with adverse outcomes. In a study of 53 subjects, the 18 with IVT had QRS times (in milliseconds) of 70, 75, 86, 90, 96, 102, 110, 114, 116, 117, 120, 130, 136, 142, 145, 152, 170, and 182. The 35 patients without IVT had QRS times of 40, 50, 65, 70, 76, 78, 80, 82, 85, 88, 88, 89, 90, 94, 95, 96, 98, 98, 100, 102, 105, 107, 109, 110, 114, 115, 120, 125, 130, 135, 138, 150, 165, 170, and 180.
(1) Display the data numerically to help understand whether QRS time is related to IVT.
(2) Display the data graphically to help understand whether QRS time is related to IVT.
(3) QRS time is commonly considered as abnormal if the value is greater than 120 ms. Generate a numerical display to help understand if abnormal QRS is related to IVT.
(4) What are the advantages and disadvantages of treating QRS as binary (above 120 ms) instead of continuous?