a can 5 inches high with a diameter of 4 inches weighs 32.0 ouces. What is the weight of a can that is 8 inches high with a diameter of 3 inches?

We can solve this with a proportion  by equating ounces and volumes of cylinders :

32 / [pi* (2)^2 * 5]  = x / [pi * (1.5)^2 * 8]    where x is the unknown no. of ounces

32 / 20  = x / 18     cross-multiply

18 * 32  = 20 * x

x = 32 * 18 / 20  = 28.8 ounces

Thanks CPhill!