\( S_5 = 4 \cdot \frac{(\frac32)^5 - 1}{\frac32 - 1} = 4 \cdot \frac{\frac24332 - 1}{\frac12} = 4 \cdot \frac{\frac21132}{\frac12} = 4 \cdot \frac21132 \cdot 2 = 8 \cdot \frac21132 = \frac168832 = 52.75 \). - Dyverse