mathematics
posted by Richelle .
What is the solution for this?
The surface area of a sphere varies in direct proportion to the square of its radius. If a sphere of radius 6cm has a surface area of 452 square cm, find, to the nearest mm, the radius of a spherewith the surface area 1000 square cm.

36/452 = r^2/1000
r^2 = 36/.452
r = 8.9 cm