# Sequence

Algebra Level 3

Given that $$x_1, x_2, \ldots,x_{16}$$ are positive real numbers such that $$\dfrac{x_1}{x_2} = \dfrac{x_2}{x_3} = \cdots = \dfrac{x_{15}} {x_{16}}$$.

If $$x_1 + x_2 + x_3 + x_4 = 20$$ and $$x_5 + x_6 + x_7 +x_8 = 320$$, find $$x_{13} + x_{14} + x_{15} + x_{16}$$.

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