Answer:
2√2
Step-by-step explanation:
We can find the relationship of interest by solving the given equation for A, the mean distance.
[tex]T^3=A^2\\\\A=\sqrt{T^3}=T\sqrt{T}\qquad\text{take the square root}[/tex]
The mean distance of planet X is found in terms of its period to be ...
[tex]D_x=T_x\sqrt{T_x}[/tex]
The mean distance of planet Y can be found using the given relation ...
[tex]T_y=2T_x\\\\D_y=T_y\sqrt{T_y}=2T_x\sqrt{2T_x}=(2\sqrt{2})T_x\sqrt{T_x}\\\\D_y=2\sqrt{2}\cdot D_x[/tex]
The mean distance of planet Y is increased from that of planet X by the factor ...
2√2