"If a small planet were located 8 times as far as the Earth's distance from the Sun, what would be its period in Earth years?" (22.5 earth years)

Question

As a note, we are given a table with all of the planets' masses and radii.

Answer 1

http://hyperphysics.phy-astr.gsu.edu/HBASE/kepler.html

see the law of periods