Answer with explanation:
The Equation which is relationship between a planet’s orbital period, T, and the planet’s mean distance from the sun, A, in astronomical units, AU.
→ 
For Planet , X

--------------------------------------(1)
And, For Planet ,Y

-----------------------------------------(2)
Dividing equation (1) by (2)

![[\frac{(T_{1})}{(T_{2})}]^2=\frac{x^3}{8 x^3}\\\\\frac{(T_{1})}{(T_{2})}=\sqrt{\frac{1}{8}}\\\\ T_{2}={2\sqrt{2}}{T_{1}}](https://tex.z-dn.net/?f=%5B%5Cfrac%7B%28T_%7B1%7D%29%7D%7B%28T_%7B2%7D%29%7D%5D%5E2%3D%5Cfrac%7Bx%5E3%7D%7B8%20x%5E3%7D%5C%5C%5C%5C%5Cfrac%7B%28T_%7B1%7D%29%7D%7B%28T_%7B2%7D%29%7D%3D%5Csqrt%7B%5Cfrac%7B1%7D%7B8%7D%7D%5C%5C%5C%5C%20T_%7B2%7D%3D%7B2%5Csqrt%7B2%7D%7D%7BT_%7B1%7D%7D)
→Orbital Period of Planet Y increases by, 2√2 times =2 ×1.414=2.828 times than planet X.