cylinder to the nearest hundredth of an inch

Question

A circular cylinder is to hold 12 gallons of liquid and is 34 inches tall. If 1 gallon is 231 cubic inches, what is the approximate radius of the cylinder to the nearest hundredth of an inch?

Answer 1

For a cylinder, V = pi(r^2)h

The volume is 12 x 231 = 2772 cubic inches

So 2772 = 3.14 x r^2 x 34

r^2 = 2772 / (3.14 x 34)

r^2 = 26

r = 5.10 inches

Note: using the pi key instead of 3.14 will give you 5.09 inches