Final answer:
An average person weighing 155 lbs has between 4.7 to 5.7 liters of blood, which is roughly 8 percent of their body weight and consists largely of water in the form of blood plasma.
Step-by-step explanation:
The average person weighing 155 lbs has approximately 4.7 to 5.7 liters of blood in their system. Blood constitutes about 8 percent of an adult's body weight. Since an adult male averages about 5 to 6 liters of blood and an adult female averages 4 to 5 liters, it's safe to say that for a person weighing 155 lbs, which is a moderate weight for an adult, the blood volume would be within this range. Knowing that the body is made up of 50-70% water with blood plasma being around 92 percent water, and understanding the composition of blood including cells and blood plasma, helps to appreciate the volume of blood within the cardiovascular system.