How to measure cardiac output noninvasively?

breathe deeply from your lower lungs - imagine a rubber ring around your waist (your diaphragm)

breathe in and try to push the ring outwards.

breathe in through your nose and out through your nose and mouth.

explanation:

answer; 4% i believe this is correct;

the gravitational force on an object increase as the mass of an object also, im not going to report you, but this question should be under the science category, not health