the average human heart beats at 70 beats per minute for a 12 - year - old. how many beats is this in one…

the average human heart beats at 70 beats per minute for a 12 - year - old. how many beats is this in one hour? write this in scientific notation. show your work.
Answer
Explanation:
Step1: Know the conversion factor
There are 60 minutes in 1 hour.
Step2: Calculate the number of heart - beats in an hour
Multiply the beats per minute by the number of minutes in an hour. So, the number of beats in an hour is $70\times60 = 4200$.
Step3: Convert to scientific notation
To write 4200 in scientific notation, we move the decimal point 3 places to the left. So, $4200=4.2\times10^{3}$.
Answer:
$4.2\times10^{3}$