As shown in the diagram above, a lever resting on a fulcrum has weights of $$w_{1} $$ pounds and $$w_{2}$$ pounds, located $$d_{1}$$ feet and $$d_{2}$$ feet from the fulcrum. The lever is balanced and $$w_{1}d_{1} = w_{2}d_{2}$$. Suppose $$w_{1}$$ is 50 pounds and $$w_{2}$$ is 30 pounds. If $$d_{1}$$ is 4 feet less than $$d_{2}$$, what is $$d_{2}$$, in feet?