Percent decrease = (original number - new number) / original number....* 100
= (45 - 27.5) / 45.....* 100
= 17.5 / 45....* 100
= 0.3888 * 100
= 38.9 % decrease <== thats rounded
Volume of the cylinder=area (circle) x height
area (circle)=πr²
r=radius=4 in.
area=π(4 in)²=16π in²
height=8 in
Volume of the cylinder=(16π in²)(8 in)=128π in³≈402.12 in³
Answer= 128π in³ or 402.12 in³