Final answer:
The closest cardiac output for a heart rate of 70 beats/min is 5.25 L/min, based on the reference indicating the mean CO and range for a resting adult's single ventricle.
Step-by-step explanation:
If the heart rate is 70 beats/min, to find the cardiac output (CO) we would also need the stroke volume (SV), which is the volume of blood pumped per beat by each ventricle of the heart. As we do not have the SV given, we rely on the provided average data that indicates the mean CO is 5.25 L/min, with a range of 4.0 to 8.0 L/min for a resting adult.
The available choices provided for the CO are 3.45 L/min, 4.55 L/min, 5.25 L/min, 8.00 L/min, and 9.85 L/min. Using the average CO data from the reference, the closest answer to the question is 5.25 L/min, which falls within the range for an individual ventricle, as indicated in the context provided.
It's important to note that this number represents the output from each ventricle separately and not the total CO for the heart.