There are two carotid arteries that feed blood to the brain, one on each side of the neck and head. One patient's carotid arteries are each 11.2 cm long and have an inside diameter of 5.3 mm . Near the middle of the left artery, however, is a 2.0-cm-long stenosis, a section of the artery with a smaller diameter of 3.5 mm.
For the same blood flow rate, what is the ratio of the pressure drop along the patient's left carotid artery to the drop along his right artery?