A person's blood pressure B (in millimeters of mercury, abbreviated mm Hg) fluctuates with the beating of the person's heart. Every 3/4 of a second, it rises from it's normal state of 100 mm Hg to a high of 120 mm Hg, drops to a low of 80 mm Hg and returns to its normal state. a) Sketch the graph that represents one complete heartbeat. b) Find a formula for the person's blood pressure B over time t.