The expression is \( \frac{3n^2}{2} \). To find the fifth term, substitute \( n = 5 \) into the expression:
\[ \frac{3 \cdot (5)^2}{2} \]
Now, perform the calculations step by step:
\[ \frac{3 \cdot 25}{2} \]
\[ \frac{75}{2} \]
So, the fifth term is \( \frac{75}{2} \).