The terms $x _ { n }$ of a sequence follow the rule $$x _ { n + 1 } = \frac { x _ { n } + p } { x _ { n } + q }$$ where $p$ and $q$ are real numbers. Given that $x _ { 1 } = 3 , x _ { 2 } = 5$, and $x _ { 3 } = 7$, find the value of $x _ { 4 }$
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The terms $x _ { n }$ of a sequence follow the rule
$$x _ { n + 1 } = \frac { x _ { n } + p } { x _ { n } + q }$$
where $p$ and $q$ are real numbers.
Given that $x _ { 1 } = 3 , x _ { 2 } = 5$, and $x _ { 3 } = 7$, find the value of $x _ { 4 }$