Week 2 – Geometric Series

Question: Find, $S_7$ when $t_1 = 4$ and $r =$ $\frac {3}{4}$

Figure out which formula we use:

to figure out the answer of the sum for a geometric series, you use

$S_n =$ $\frac {a(r^n-1)}{r-1}$

Slove the problem with that equation

$S_{10} =$ $\frac {4 ( \frac {3}{4}^{5}-1)}{ \frac {3}{4}-1}$