To simplify the expression \( 3^8 \cdot 3^3 \) using the Product Rule of Exponents, you can add the exponents of the same base. The Product Rule states:
\[ a^m \cdot a^n = a^{m+n} \]
In this case, the base \( a \) is \( 3 \), \( m = 8 \), and \( n = 3 \). Applying the rule:
\[ 3^8 \cdot 3^3 = 3^{8+3} = 3^{11} \]
So, the simplified expression is:
\[ 3^{11} \]