Blood filtered by the kidneys per minute is roughly ___ of the blood pumped out by each ventricle of the heart in a minute.

Both the kidneys filter about 1100-1200 mL of blood per minute. This is about 1/5^th of the blood pumped out by each ventricle of the heart in a minute (cardiac output). Cardiac output of the human heart is about 72 x 72 = 5,040 mL.