Final answer:
The normal heart rate of a newborn baby may vary, but the resting heart rate is typically around 120 beats per minute (bpm). As the baby grows, the heart rate gradually decreases until young adulthood and then gradually increases again with age.
Step-by-step explanation:
The normal heart rate of a newborn baby may vary, but the resting heart rate is typically around 120 beats per minute (bpm).
As the baby grows, the heart rate gradually decreases until young adulthood and then gradually increases again with age.
It's important to note that heart rates can vary with exercise and fitness levels as well.