Final answer:
The stroke volume divided by end diastolic volume calculates the ejection fraction, a percentage indicating how much blood is ejected from the heart each beat, normally ranging from 55% to 70%.
Step-by-step explanation:
The stroke volume (SV) divided by end diastolic volume (EDV) is used to calculate the ejection fraction, which represents the percentage of blood ejected from the heart with each contraction. The formula for ejection fraction is SV/EDV, and despite its name being 'fraction,' it is expressed as a percentage. Normal ejection fractions range from approximately 55% to 70%, with an average of around 58%. Stroke volume, typically between 70-80 mL, is the amount of blood pumped out of the ventricles during each heartbeat, while the EDV, which is about 130 mL, is the volume of blood in the ventricles at the end of atrial systole, just before they contract.