Theo bài ra ta có: $\left\{ \begin{matrix}   {{P}_{1000}}={{P}_{0}}.{{e}^{1000i}}  \\   {{P}_{3000}}={{P}_{0}}.{{e}^{3000i}}  \\\end{matrix} \right.$ $\Leftrightarrow \left\{ \begin{matrix}   {{\left( {{P}_{1000}} \right)}^{3}}={{({{P}_{0}})}^{3}}.{{e}^{3000i}}  \\   {{P}_{3000}}={{P}_{0}}.{{e}^{3000i}}  \\\end{matrix} \right.\Leftrightarrow {{P}_{3000}}=\frac{{{\left( {{P}_{1000}} \right)}^{3}}}{{{({{P}_{0}})}^{2}}}\approx 530$