The equation Tsquared=Acubed shows the relationship between a planet’s orbital period, T, and the planet’s mean distance from the sun, A, in astronomical units, AU. If the orbital period of planet Y is twice the orbital period of planet X, by what factor is the mean distance increased?

1. 2 ^1/3
2. 2^1/2
3. 2^2/3
4. 2^3/2