A dye is injected into the circulating blood volume to measure a patient’s cardiac output, which is the volume flow rate of blood out of the left ventricle of the heart. In other words, cardiac output is the number of liters of blood your heart pumps in a minute. For a person at rest, the rate might be 5 or 6 liters per minute. If you are a trained marathon runner running a marathon, your cardiac output can be as high as 30 L/min. The data below shows the response of an individual when 5 mg of dye was injected into the venous system.

Fit a polynomial curve through the data points and use the function to approximate the patient’s cardiac output, which can be calculated by:

Time (s) 2 6 9 12 15 18 20 24 Concentration (mg L) 0 15 32 41 34 2 1 0