Calculate the entropy for the parent node and see how much uncertainty exists by splitting on "Balance." The blue circles represent people from the "payoff" class and the red circles are people from the "default" class. Splitting the parent node on the "Balance" attribute gives us two child nodes: $"<$ $$50$K$$ or $"$ $$50$K$."$ Review the graphic below to see how the data is split. What is the entropy of the root node if we split on $$Balance$"?$