An aluminum soda can holds 12 fl oz. Enter the least amount of aluminum needed to make the can: Use the given volume to find a formula for the can's height h in terms of its radius r, substitute into a formula for the can's surface area, and use trial values to determine the values of r and h, to the nearest tenth of an inch, that minimize the can's surface area. (Hint: 1 fl oz=1.73 in)

The least amount of aluminum is needed when r is ___ in.
The least amount of aluminum is needed when h is ___in.