Explanation:
it can improve muscle strength and boost your endurance.
it also delivers oxygen and nutrients to your tissues
Answer:
Standard deviation = 3
Explanation:
Given


Required
Determine the standard deviation
First, we need to determine the variance;

This gives:



Know that:

Where SD represents standard deviation
This gives

Take square root


As per the question the mass of the boy is 50 kg.
The boy sits on a chair.
We are asked to calculate the force exerted by the boy on the chair at sea level.
The force exerted by boy on the chair while sitting on it is nothing else except the force of gravity of earth i.e the weight of the body .The direction of that force is vertically downward.
At sea level the acceleration due to gravity g = 9.8 m/s^2
Hence the weight of the boy
[m is the mass of the body]
we have m = 50 kg.
Hence w = 50 kg ×9.8 m/s^2
=490 N kg m/s^2
= 490 N
Here newton [N] is the unit of force.
It's a quantitative observation because it includes numerical data.