Final Answer:
The diameter of the new globe is 9.58 m. None of the given options is answer.
Step-by-step explanation:
The volume of a sphere is given by the formula:

where V is the volume of the sphere and r is the radius of the sphere.
We are given that the volume of a globe varies as the cubic of its radius. This means that the volume of a globe is proportional to the cube of its radius. We can represent this mathematically as:

where k is a constant of proportionality.
We are also given that three solid globes of diameter 11/2, 2, and 21/2 meters are melted and formed into a new solid globe. This means that the total volume of the three melted globes is equal to the volume of the new solid globe. We can express this mathematically as:

Simplifying this equation, we get:

Combining like terms, we get:

Dividing both sides by (4/3)π, we get:

Taking the cube root of both sides, we get:

Since the diameter is twice the radius, the diameter of the new globe is 2 * 4.79 m = 9.58 m. None of the given options is answer.