Final answer:
The volume of the water bottle is approximately 1.00531 liters.
Step-by-step explanation:
To find the volume of the water bottle, we can use the formula for the volume of a cylinder: V = pi * r^2 * h, where r is the radius and h is the height of the cylinder.
Given that the radius of the water bottle is 4 cm and the height is 20 cm, we can substitute these values into the formula:
V = pi * 4^2 * 20
Calculating this, we find that the volume of the water bottle is approximately 1005.31 cubic centimeters, which can also be written as 1.00531 liters.