Write a function average_of_4 that computes the average of four real numbers. Write a function cone_volume(r, h) that returns the volume of a cone. The formula for the volume of a cone is V = Sr2h/3,...

Write a function average_of_4 that computes the average of four real numbers.

Write a function cone_volume(r, h) that returns the volume of a cone. The formula for the volume of a cone is V = Sr2h/3, where r is the radius of the base and h is

its height.