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A and B are independent by definition 4.7.1 provided
\begin{equation*} P(A \cap B) = P(A) P(B). \end{equation*}
Using the provided values, notice that
\begin{equation*} P(A \cap B) = 0.31 \end{equation*}
but
\begin{equation*} P(A)P(B) = 0.43 \cdot 0.72 = 0.3096. \end{equation*}
Since these are not equal (regardless how close) then A and B are not independent.
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